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Home My WebLink AboutAPA4044SlUns DEPARTMENT OF :mE INTERIOR el"Admmt.atratlon BIlYiLrenllllental As ment for TI'.D8IIIlISa on Syatems for Devil Canyon and other Potential Units of The Upper Susitna Ri ver Project September 19.75 SITHA HSMISSIOH SYSTEM IRONMEHTAL SSESSMENT FT ..~ SlUns DEPARTMENT OF :mE INTERIOR el"Admmt.atratlon BIlYiLrenllllental As ment for TI'.D8IIIlISa on Syatems for Devil Canyon and other Potential Units of The Upper Susitna Ri ver Project September 19.75 SITHA HSMISSIOH SYSTEM IRONMEHTAL SSESSMENT FT ..~ _iDS DEPARTMENT OF :mE INTERIOR Al..~a el"Admmt.atratlon BIlYiLNDllllental As ment for T".D8IIIua on Syatems for Devil Canyon and other Potential Units of The Upper Susitna Ri ver Project September 19.75 SITHA HSMISSIOH SYSTEM IRONMEHTAL SSESSMENT FT ..~ -~·-'.'\.·"""·l.0ANCHORAGE.-1!ASk.,[1197PrefaceTheAlaskaPowerAdministrationiscooperatingwiththeCorpsofEngineersintheirevaluationofDevilCanyonandotherpotentialunitsoftheUpperSusitnaRiverProjectundertheJanuary,1972,studyresolutionbytheU.S.SenatePublicWorksCommittee.AsrequestedbytheCorps,andconsistantwithAPA'splanningandpowermarketresponsibilities,APAisprovidingthetransmissionsystemandpowermarketanalysesfortheCorpsstudies.AuthoritiesforthisworkincludeSection5oftheFloodControlActof1944concerningtransmissionandmarketingofpowerfromCorpsofEngineersProjects,andtheActofAugust9,1955,concerningInteriorDepartmentinvestigationsofAlaskawaterandpowerdevelopmentpotential.Thisreportisapreliminaryenvironmentalassessmentfortheprojecttransmissionfacilities.Itisbeingcirculatedinpreliminarydraftforinformalcomments;basedoncommentsreceived,thedraftwillbemodifiedandforwardedtotheCorpsfortheiruseinpreparationofthedraftEnvironmentalImpactStatementfortheproject.Thisdraftaddressesonlytheproposedtransmissionfacilities;itdoesnotcoverenvironmentalimpactsofthehydroelectricdevelopmentandalternativestohydroelectricdevelopment.'joAergedwithA.R.L.I.S.~NCHORAGE.ALASKA.Est.1997ARLISAlaskaResourcesLibrary&InformationServicesAnchorage,Alaska-~·-'.'\.·"""·l.0ANCHORAGE.-1!ASk.,[1197PrefaceTheAlaskaPowerAdministrationiscooperatingwiththeCorpsofEngineersintheirevaluationofDevilCanyonandotherpotentialunitsoftheUpperSusitnaRiverProjectundertheJanuary,1972,studyresolutionbytheU.S.SenatePublicWorksCommittee.AsrequestedbytheCorps,andconsistantwithAPA'splanningandpowermarketresponsibilities,APAisprovidingthetransmissionsystemandpowermarketanalysesfortheCorpsstudies.AuthoritiesforthisworkincludeSection5oftheFloodControlActof1944concerningtransmissionandmarketingofpowerfromCorpsofEngineersProjects,andtheActofAugust9,1955,concerningInteriorDepartmentinvestigationsofAlaskawaterandpowerdevelopmentpotential.Thisreportisapreliminaryenvironmentalassessmentfortheprojecttransmissionfacilities.Itisbeingcirculatedinpreliminarydraftforinformalcomments;basedoncommentsreceived,thedraftwillbemodifiedandforwardedtotheCorpsfortheiruseinpreparationofthedraftEnvironmentalImpactStatementfortheproject.Thisdraftaddressesonlytheproposedtransmissionfacilities;itdoesnotcoverenvironmentalimpactsofthehydroelectricdevelopmentandalternativestohydroelectricdevelopment.'joAergedwithA.R.L.I.S.~NCHORAGE.ALASKA.Est.1997ARLISAlaskaResourcesLibrary&InformationServicesAnchorage,Alaska ContentsTitlePreface.ContentsINTRODUCTIONDESCRIPTIONOFTHEPROPOSEDACTIONTHECORRIDORSSusitnaCorridorNenanaCorridorDeltaCorridorMatanuskaCorridorENVIRONMENTALASSESSMENTOFCORRIDORSSummaryMatrixes.Susitna-lNenana-lSusitna-2Susitna-3Susitna-4Nenana-2Nenana-3Nenana-4Nenana-5Matanuska-lMatanuska-2Delta....ENVIRONMENTALIMPACTSOFCORRIDORSSummaryMatrixes.Susitna-lNenana-1Susitna-2Susitna-3Susitna-4Nenana-2Nenana-3Nenana-4Nenana-5Matanuska-lMatanuska-2Delta. , . .iiPageNo.iii15111212151518192324262627272728282930313334384247505356596163667175ContentsTitlePreface.ContentsINTRODUCTIONDESCRIPTIONOFTHEPROPOSEDACTIONTHECORRIDORSSusitnaCorridorNenanaCorridorDeltaCorridorMatanuskaCorridorENVIRONMENTALASSESSMENTOFCORRIDORSSummaryMatrixes.Susitna-lNenana-lSusitna-2Susitna-3Susitna-4Nenana-2Nenana-3Nenana-4Nenana-5Matanuska-lMatanuska-2Delta....ENVIRONMENTALIMPACTSOFCORRIDORSSummaryMatrixes.Susitna-lNenana-1Susitna-2Susitna-3Susitna-4Nenana-2Nenana-3Nenana-4Nenana-5Matanuska-lMatanuska-2Delta. , . .iiPageNo.iii15111212151518192324262627272728282930313334384247505356596163667175 MITIGATIONOFIMPACTS79Soils. . .80Vegetation.....82Wildlife. . . . . . .83ExistingDevelopments84ScenicQuality-Recreation84ADVERSEENVIRONMENTALIMPACTS86RELATIONSHIPBETWEENSHORT-TERMUSESOFTHEENVIRONMENTANDLONG-TERMPRODUCTIVITY. .91IRREVERSIBLEANDIRRETRIEVABLECOMMITMENTSOFRESOURCES. . . . . . . . . . . . . . . . . . .94OTHERALTERNATIVESTOTHEPROPOSEDACTION97SharingofRights-of-Way. . . . .98UndergroundTransmissionSystems100DirectCurrentTransmission.. . .104AlternativeSystemPlans.....105AlternativeMethodsofConstructionandMaintenance105AlternativeEndpoints. . . .108NoAction(non-construction)109ACKNOWLEDGEMENTS. . . . . .111APPENDIXESI,11,IIIiiiMITIGATIONOFIMPACTS79Soils. . .80Vegetation.....82Wildlife. . . . . . .83ExistingDevelopments84ScenicQuality-Recreation84ADVERSEENVIRONMENTALIMPACTS86RELATIONSHIPBETWEENSHORT-TERMUSESOFTHEENVIRONMENTANDLONG-TERMPRODUCTIVITY. .91IRREVERSIBLEANDIRRETRIEVABLECOMMITMENTSOFRESOURCES. . . . . . . . . . . . . . . . . . .94OTHERALTERNATIVESTOTHEPROPOSEDACTION97SharingofRights-of-Way. . . . .98UndergroundTransmissionSystems100DirectCurrentTransmission.. . .104AlternativeSystemPlans.....105AlternativeMethodsofConstructionandMaintenance105AlternativeEndpoints. . . .108NoAction(non-construction)109ACKNOWLEDGEMENTS. . . . . .111APPENDIXESI,11,IIIiii TableofFigures1.TheRailbelt2.AlternativeTransmissionLineStructures3.AlternativeTransmissionLineStructures4.AlternativeSystemPlans5.AlternativeTransmissionCorridors6.TransmissionCorridorSegmentsivPageNo.289131416TableofFigures1.TheRailbelt2.AlternativeTransmissionLineStructures3.AlternativeTransmissionLineStructures4.AlternativeSystemPlans5.AlternativeTransmissionCorridors6.TransmissionCorridorSegmentsivPageNo.289131416 FigureI75A.P.A.-JULY1975MAP50Scole-Mile$,RAILBELT25THE,/,~sUNITEDSTATESDEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATION2FigureI75A.P.A.-JULY1975MAP50Scole-Mile$,RAILBELT25THE,/,~sUNITEDSTATESDEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATION2 INTRODUCTIONThetransmissionsystemsttidiesJoi-theUpp~i-SusitnaRiverProje'ctareofpre-authorizationorfeasibilityj~liade.Theyconsist?fev~ll1a~bnofalternativecorridorlocationsfromtheviewpointsofengineering.costs,andenvironment;reconnaissancestudiesoftransmissionsystemsneededforalternativeprojectdevelopmeJ:ltplansf"ruseinov~r~llp~oj~ctformulationstudies;consideration()falternatiyetr~smissi0J:lte~nJ:lb1~gies;andfeasibilitygradedesignsandcostestimatesfortheI't;eferr~~tt;ay~missionplan.Thesestudiesdealwithgeneralcorridorlocation;'thel~oi-edEitailedstudiesfollowingprojeetauthorii"ti"nwouldincludefinal;fri'thegroundrotitelocation.Thepurposeofapreliminarytransll1issioncorridorsurveyistoeliminatethosewhichdonotappeartobefeasible.whetherfortechnical,economic,orenvironmentalreasons.Thepreliminarysurveythenanalyzesthoseremainingcorridorsandpre~~J:ltsthe,ciat"onthevariousalternativecorridorsinsuchawaysothatcomparisons.canbemade.Atthispoint,itisnotwithinthescopeofthepreliminarysurveytoshowpreferenceforsomecorridorsoverothers,onlytorejectobviouslyunfeasibleonesandtoanalyzethef",asibleones.Furtheranalysisthenprovidesthebasisfortheselectionofthepreferredsystemplan.Basically,theselectionofcorridorsdevolvesontheneedtotransmitpc••"rfromagenerationsite--th"jpevilCaJ:lyon-Watanadamsites--trtwoloadcenters,AnchorageandFairbanks(SeeFigure1).TheloadcentersarealmostequallytothenorthandsouthoftheUpperSusitnacomplex,andareconnecteditoeachotherbytwobasiccorridorstheAnchorage-FairbanksHighway/AlaskaRailroadandtheGlenn/RichardsonHighway.Thealternativesareallvariationsuponthesetwobasiccorridors,whicharedictatedbythetopographyandclimateoftheRailbeltarea.AlthoughthemosteconomicaltransIllissioncorridoristheoreticallyastraightlinejoininggeneration~t~"andload!cjenter,physicalandsocialfactorsforcedeviationsfromthisshortest-distanceideal.Thus,itcanoftenhappenthatphysicalandsocialfactorsareinoppositiontoeconomicfactors,andabalanc~hastobefound.Thisstriving~orabalanceresultsinalternatiy~~!;fromwhich,eventuallyamostdesirablecorridorhastobechosen;3INTRODUCTIONThetransmissionsystemsttidiesJoi-theUpp~i-SusitnaRiverProje'ctareofpre-authorizationorfeasibilityj~liade.Theyconsist?fev~ll1a~bnofalternativecorridorlocationsfromtheviewpointsofengineering.costs,andenvironment;reconnaissancestudiesoftransmissionsystemsneededforalternativeprojectdevelopmeJ:ltplansf"ruseinov~r~llp~oj~ctformulationstudies;consideration()falternatiyetr~smissi0J:lte~nJ:lb1~gies;andfeasibilitygradedesignsandcostestimatesfortheI't;eferr~~tt;ay~missionplan.Thesestudiesdealwithgeneralcorridorlocation;'thel~oi-edEitailedstudiesfollowingprojeetauthorii"ti"nwouldincludefinal;fri'thegroundrotitelocation.Thepurposeofapreliminarytransll1issioncorridorsurveyistoeliminatethosewhichdonotappeartobefeasible.whetherfortechnical,economic,orenvironmentalreasons.Thepreliminarysurveythenanalyzesthoseremainingcorridorsandpre~~J:ltsthe,ciat"onthevariousalternativecorridorsinsuchawaysothatcomparisons.canbemade.Atthispoint,itisnotwithinthescopeofthepreliminarysurveytoshowpreferenceforsomecorridorsoverothers,onlytorejectobviouslyunfeasibleonesandtoanalyzethef",asibleones.Furtheranalysisthenprovidesthebasisfortheselectionofthepreferredsystemplan.Basically,theselectionofcorridorsdevolvesontheneedtotransmitpc••"rfromagenerationsite--th"jpevilCaJ:lyon-Watanadamsites--trtwoloadcenters,AnchorageandFairbanks(SeeFigure1).TheloadcentersarealmostequallytothenorthandsouthoftheUpperSusitnacomplex,andareconnecteditoeachotherbytwobasiccorridorstheAnchorage-FairbanksHighway/AlaskaRailroadandtheGlenn/RichardsonHighway.Thealternativesareallvariationsuponthesetwobasiccorridors,whicharedictatedbythetopographyandclimateoftheRailbeltarea.AlthoughthemosteconomicaltransIllissioncorridoristheoreticallyastraightlinejoininggeneration~t~"andload!cjenter,physicalandsocialfactorsforcedeviationsfromthisshortest-distanceideal.Thus,itcanoftenhappenthatphysicalandsocialfactorsareinoppositiontoeconomicfactors,andabalanc~hastobefound.Thisstriving~orabalanceresultsinalternatiy~~!;fromwhich,eventuallyamostdesirablecorridorhastobechosen;3 methodofanalysisforthealternativesusestheshortestsegments"h"""nintersectionsofalternativecorridorsastheunitsofevaluations;mayvaryinlengthfrom15toover100miles.Thesesegmentsevaluatedonasetofphysicalandsocialcriteria,butarenotbecomparedtoeachother.Theseevaluationsareshowninthem'L{rJlX.'Sonpages19-22andpages34-37.U~'lllgthesesegmentsasbasicunitsincombination,severalalternativecanbedevisedandcanthenbecompared.Tosaverepetition,sE'glnentscommontoalternativecorridorsbeingcomparedcanbeomittedthecomparison.ThecorridorpresentedintheDescriptionofProposedActionisthatroutewhichproducestheminimumadverseconsistentwitheconomicfeasibility.4methodofanalysisforthealternativesusestheshortestsegments"h"""nintersectionsofalternativecorridorsastheunitsofevaluations;mayvaryinlengthfrom15toover100miles.Thesesegmentsevaluatedonasetofphysicalandsocialcriteria,butarenotbecomparedtoeachother.Theseevaluationsareshowninthem'L{rJlX.'Sonpages19-22andpages34-37.U~'lllgthesesegmentsasbasicunitsincombination,severalalternativecanbedevisedandcanthenbecompared.Tosaverepetition,sE'glnentscommontoalternativecorridorsbeingcomparedcanbeomittedthecomparison.ThecorridorpresentedintheDescriptionofProposedActionisthatroutewhichproducestheminimumadverseconsistentwitheconomicfeasibility.4 DESCRIPTIONOFTHEPROPOSEDACTIONTheproposedactionincludestheconstructionandoperationofatransmis-sionsystemtodeliverpowergeneratedbydamsandpowerplantsontheUpperSusitnatothetwoprimaryloadcentersofAnchorageandFairbanks,andperhapsotherloadcentersthatmayprovefeasible.Thedesignandlocationofthislinewillprovideforthemosteconomicalconstructionandreliableoperationconsistentwithminimaldamagetotheenvironment.Ifapproved,constructionwouldbeginin1986.Asubsidiarypurposeinthecconstructionofthislinewill,betheinter-connectionofthetwolargestelectricpowerdistributiongridsintheStateofAlaska;thiswillresultinincreasedreliabilityofserviceandlowercostofpowergeneration.Theproposedcorridorruns'fromtheDevilCanyonpowerhousewesttvGoldCreek,then~outhwestialongtheSusitnaRiverandtheAlaskaRailroadtoTalkeetna.cFrom'TalkeetnathecorridorfollowstheeastbankoftheSusitnaRiver/totheNancyLakeareaandthenduesouthtoPointMacKenzie."ThesecondhalfofthecorridorrunsfromGoldCreeknorthtoChulitnaandthenparallelstheAnchorage-FairbanksHighwayandtheAlaskaRailroadthroughBroadPass,theNenanaCanyon,andtoHealy.FromHealythecorridorwillfollowtheexistingGVEA138kvtransmissionlinetotheexistingsubstationatGoldHillLrrester,althoughtheexistingright-of-waymaynotnecessarilybeused.Thesectionofcorridor'fromDevilCanyontoPointMacKenzieabout140miles;fromDevilCanyontoEsterisabout200miles.Thevoltageofthesection'fromDevilCanyontoAnchorageis345kvandthatofthesectionfromDevilCanyontoFairbanksis230kv.Bothsectionsaredoublecircuitandwillrequireaclearedright-of-wayofapproximately125'feebTowerswillbeeithersteeloraluminumandofthefree-standing,type;,althoughdependinguponfinaldesignandlocalconditions,guyedtowersmaybeusedinsomeareas.Theconductorsareofaluminumconductorreinforcedwithsteel.Thesequenceoffinalrouting,,~mdconstructionfollowsageneralsequenceoffinalsurveytolocatetowersandclearingwidths,clearingandaccessconstruction;erectionoftowers,stringing,tensioning,andright-of-wayrestoration.6DESCRIPTIONOFTHEPROPOSEDACTIONTheproposedactionincludestheconstructionandoperationofatransmis-sionsystemtodeliverpowergeneratedbydamsandpowerplantsontheUpperSusitnatothetwoprimaryloadcentersofAnchorageandFairbanks,andperhapsotherloadcentersthatmayprovefeasible.Thedesignandlocationofthislinewillprovideforthemosteconomicalconstructionandreliableoperationconsistentwithminimaldamagetotheenvironment.Ifapproved,constructionwouldbeginin1986.Asubsidiarypurposeinthecconstructionofthislinewill,betheinter-connectionofthetwolargestelectricpowerdistributiongridsintheStateofAlaska;thiswillresultinincreasedreliabilityofserviceandlowercostofpowergeneration.Theproposedcorridorruns'fromtheDevilCanyonpowerhousewesttvGoldCreek,then~outhwestialongtheSusitnaRiverandtheAlaskaRailroadtoTalkeetna.cFrom'TalkeetnathecorridorfollowstheeastbankoftheSusitnaRiver/totheNancyLakeareaandthenduesouthtoPointMacKenzie."ThesecondhalfofthecorridorrunsfromGoldCreeknorthtoChulitnaandthenparallelstheAnchorage-FairbanksHighwayandtheAlaskaRailroadthroughBroadPass,theNenanaCanyon,andtoHealy.FromHealythecorridorwillfollowtheexistingGVEA138kvtransmissionlinetotheexistingsubstationatGoldHillLrrester,althoughtheexistingright-of-waymaynotnecessarilybeused.Thesectionofcorridor'fromDevilCanyontoPointMacKenzieabout140miles;fromDevilCanyontoEsterisabout200miles.Thevoltageofthesection'fromDevilCanyontoAnchorageis345kvandthatofthesectionfromDevilCanyontoFairbanksis230kv.Bothsectionsaredoublecircuitandwillrequireaclearedright-of-wayofapproximately125'feebTowerswillbeeithersteeloraluminumandofthefree-standing,type;,althoughdependinguponfinaldesignandlocalconditions,guyedtowersmaybeusedinsomeareas.Theconductorsareofaluminumconductorreinforcedwithsteel.Thesequenceoffinalrouting,,~mdconstructionfollowsageneralsequenceoffinalsurveytolocatetowersandclearingwidths,clearingandaccessconstruction;erectionoftowers,stringing,tensioning,andright-of-wayrestoration.6 Thefinalsurveywillinvolvephotogrammetricdeterminationofclearingwidthstominimizetheamountofclearing;notonlyisthismoreeconomical,butitalsoavoidsthemethodoftotalclearingwithinsetdistancesfromthecenterline,Finaltowerlocationsarealsodeterminedatthistime;towerspacingsareusuallyontheorderoffourorfivepermile,butwillbespacedcloserasconditionswarrant,Towerdesignswillbedeterminedinthefinaldesign;'varyingcondi.tionsmaycallforseveraldesignsbeingused,Freestandingtowersaremoreeasilyconstructedonsectionswithgoodaccessroads;guyedtowersaremoresuitableforhelicopterconstruction·,Variousguyeqandfree-standingtowerdesigns,forsingleanddollblecircuits,andseveralalternatestructuresforuseinlieuoftowersinspecialcircuIIistancesareshownonFigures2and3.Inheavilyforestedareas,clearingwillbedonebybrushbladesonbulldozersandbyhandremovalofindividualdangertreesoutside01;hemainclearedstrip,Dangertreesarethosetreesthatmaygrowtosuchasizewithinfiveortenyearsthattheymayfallwithinasetdistancefromaconductorortower.Distancefromthecenterline,growthrate,andmaximumcbt~in.ableheightwilldeterminedangertrees,DisposalofclearedmaterialsmayvaryfroIllsellingofmerchantabletimbertochippingorburningofslash.Insectionswherepermanentaccessroadsarerequired,theroadwillbehuiltandmaintainedtoastandardsuitableforfour-wheelvehicles.Notallsectionswillhaveaccessroads;incriticalareas,wintercon-"iuction,orhelicopterconstructionwillbeused.Right-of-wayrestorationafterconstructionincludesremovaloftemporarystructuresandtemporaryroads,disposalofslashandrefuseandrevegetation.Insomecases,itmaybenecessarynotonlytomaintainaccessroads,buttoupgradethemifitisdeterminedbytheStateDepartmentofHighwaysthatsucharoadwouldbeasuitableadditiontothesecondaryroadsystem.Alongsomesections,periodicsuppressionoftallvegetationwillbenecessary.ThiswillbeaccoIllplishedwithmanuala.pplicationofherbicidesorhandclearing,orboth.Vegetationmaintenance'Nillneedtoberepeatedeveryfiveyearsorlonger,7Thefinalsurveywillinvolvephotogrammetricdeterminationofclearingwidthstominimizetheamountofclearing;notonlyisthismoreeconomical,butitalsoavoidsthemethodoftotalclearingwithinsetdistancesfromthecenterline,Finaltowerlocationsarealsodeterminedatthistime;towerspacingsareusuallyontheorderoffourorfivepermile,butwillbespacedcloserasconditionswarrant,Towerdesignswillbedeterminedinthefinaldesign;'varyingcondi.tionsmaycallforseveraldesignsbeingused,Freestandingtowersaremoreeasilyconstructedonsectionswithgoodaccessroads;guyedtowersaremoresuitableforhelicopterconstruction·,Variousguyeqandfree-standingtowerdesigns,forsingleanddollblecircuits,andseveralalternatestructuresforuseinlieuoftowersinspecialcircuIIistancesareshownonFigures2and3.Inheavilyforestedareas,clearingwillbedonebybrushbladesonbulldozersandbyhandremovalofindividualdangertreesoutside01;hemainclearedstrip,Dangertreesarethosetreesthatmaygrowtosuchasizewithinfiveortenyearsthattheymayfallwithinasetdistancefromaconductorortower.Distancefromthecenterline,growthrate,andmaximumcbt~in.ableheightwilldeterminedangertrees,DisposalofclearedmaterialsmayvaryfroIllsellingofmerchantabletimbertochippingorburningofslash.Insectionswherepermanentaccessroadsarerequired,theroadwillbehuiltandmaintainedtoastandardsuitableforfour-wheelvehicles.Notallsectionswillhaveaccessroads;incriticalareas,wintercon-"iuction,orhelicopterconstructionwillbeused.Right-of-wayrestorationafterconstructionincludesremovaloftemporarystructuresandtemporaryroads,disposalofslashandrefuseandrevegetation.Insomecases,itmaybenecessarynotonlytomaintainaccessroads,buttoupgradethemifitisdeterminedbytheStateDepartmentofHighwaysthatsucharoadwouldbeasuitableadditiontothesecondaryroadsystem.Alongsomesections,periodicsuppressionoftallvegetationwillbenecessary.ThiswillbeaccoIllplishedwithmanuala.pplicationofherbicidesorhandclearing,orboth.Vegetationmaintenance'Nillneedtoberepeatedeveryfiveyearsorlonger,7 I• I t-Lj-J I• I -2 I , I I i IIYHYI I ~Lotj -00 '" I I ___~__.1_.,,_._ Ie ------.~-.54'~·----1 T~---~/1 I I• SINGLE CIRCUIT SINGLE CIRCUIT FLAT CONFIGURATION DELTA CONFIGURATION FREE-STANDING TOWERS Source'Edison Electric InSfitute ::!'! ""C ~co N A.P.A:-JANUARY 1975 ALTERNATIVE TRANSMISSION L NE STRUCTURES DOUBLE CIRCUIT STACK CONFIGURATION NOTE'STRUCTURES DEPICTED ARE DESIGNED FOR 345 KV.230KV STRUCTURES ARE SLIGHTLY SMALLER. UNITED STATES DEPARTMENT OF THE INTERIOR ALASKA"POWER.AO~~t1N ISTRATION SINGLE CIRCUIT FLAT.CONFIGURATION GUYED TOWERS I•I -54'~II----; I• SINGLE CIRCU FLAT CONFIGURATION -T--- SINGLE CIRCUIT SINGLE CIRCUIT FLAT CONFIGURATION DELTA CONFIGURATION FREE-STANDING TOWERS I• I I I••~--4d--~ I• I --"---'---- -------~--54'------1 T---I I• ALTERNATIVE TRANSMISSION LINE STRUCTURES A.P.A:-JANUARY 1975 DOUBLE CIRCUIT STACK CONFIGURATION NOTE'STRUCTURES DEPICTED ARE DESIGNED FOR 345 KV_230KV STRUCTURES ARE SLIGHTLY SMALLER. UNITED STATES DEPARTMENT OF THE INTERIOR ALASKA"POWER,ADMI N ISTRATl9N SINGLE CIRCUIT FLAT CONFIGURATION GUYED TOWERS I•I -54'--"'----1 I• SINGLE CIRCU FLAT CONFIGURATION Source'Edison Electric Insfitute -'"---\"'"X~/I L r--3J Oro '" \I 1 40 ', r orvlQ -~It>< I I 56'T~!~ ro • .- SINGLE CIRCUIT <D I DELTA CONFIGURATION GUYED TOWER SINGLE CIRCUIT METAL H-FRAME STRUCTURE SINGLE CIRCUIT WOOD H-FRAME STRUCTURE ::!l '"c ii1 A.P,A.-JANUARY 1975 •VI NOTE'STRUCTURES DEPICTED ARE DESIGNED FOR 345 KV.230 KV STRUCTURES ARE SLIGHTLY SMALLER. 156~.~ T-I/~"'I l!\.1; to .., . -Ie _I 56'Tn ~l -.-R y......;;<. /I ~ L r--3J Oro '" \/ <D SINGLE CIRCUIT DELTA CONFIGURATION GUYED TOWER SINGLE CIRCUIT METAL H-FRAME STRUCTURE SINGLE CIRCUIT WOOD H-FRAME STRUCTURE ::!l '"c ii1 A.P,A.-JANUARY 1975 VI NOTE'STRUCTURES DEPICTED ARE DESIGNED FOR 345 KV.230 KV STRUCTURES ARE SLIGHTLY SMALLER. I I• PeriodicinspectionofthelinewillbedoneJromtheair,bylessfrequentinspectionfromtheground.Inspectionwill",p,vf,~lpotentialfailureoftowercomponentssuchasvibrationdampandguylines;conditionoftowerfootings;conditionof<COl1cll1,ct(),..,presenceofdangertrees;andconditionofacceSSroads.Alternativemethodsofconstructionandmaintenancewhichwererefei'redtoabove,willbediscussedingreaterdetailinthesectiontotheProposedAction.ThepreferredsystemplanwaschosenbyAlaskaPowerJ">."mlnlSl.ra.m1J:lafterpreliminarystudyofallfeasiblecorridorsjoiningtheSusitnacomplextoAnchorageandFairbanks.Themostfe;,siibIeCUEnClOrwasselectedonthebasisofcost,reliability,andpotentialen.vi.rC'riiri.iiiitalimpact;theremainingcorridorsrepresentalternativesofdegreesoffeasibility.Thefollowingsectionswilldiscusstheproposedcorridoralternativecorridorsequally;nodifferentiationwillbereflectstheprocessbywhichthepreferredcorridorwasinwhichnopreferencewasgiventoanyonecorridoruntilhadbeengivenequalconsideration.10Periodicinspectionofthelinewillbedone,fromtheair,bylessfrequentinspectionfromtheground.Inspectionwill",p,vf,~lpotentialfailureoftowercomponentssuchasvibrationdampandguylines;conditionoftowerfootings;conditionof<COl1cll1,ct(),..,presenceofdangertrees;andconditionofacceSSroads.Alternativemethodsofconstructionandmaintenancewhichwererefei'redtoabove,willbediscussedingreaterdetailinthesectiontotheProposedAction.ThepreferredsystemplanwaschosenbyAlaskaPowerJ">."mlnlSl.ra.m1J:lafterpreliminarystudyofallfeasiblecorridorsjoiningtheSusitnacomplextoAnchorageandFairbanks.Themostfe;,siibIeCUEnClOrwasselectedonthebasisofcost,reliability,andpotentialen.Virc,riiri.iiiitalimpact;theremainingcorridorsrepresentalternativesofdegreesoffeasibility.Thefollowingsectionswilldiscusstheproposedcorridoralternativecorridorsequally;nodifferentiationwillbereflectstheprocessbywhichthepreferredcorridorwasinwhichnopreferencewasgiventoanyonecorridoruntilhadbeengivenequalconsideration.10 THECORRIDORSThealternativesystemplansrepresentonlygeneralcorridors,anddonotattempttodefineanactualright-of-way.Thusthealternativesdonotdistinguishamongmanyminorvariations,andasaresult,arefairlyflexible.Therearefourgroupsofalternatives:first,thosethatleadfromDevilCanyon-WatanatoAnchorageviatheSusitnawatershed;second,thosethatleadtoFairbanksviatheNenanaandTananadrainage;third,thosethatleadtoFairbanksviatheDeltaandTananadrainages;andfourth,thosethatleadtoAnchorageviatheCopperandMatanuskadrainages(seeFigures4and5,andStripMapsinAppendixII).SusitnaCorridorsTherearebasicallyfourfeasiblec,.,.idorswhichconnectDevilCanyontoAnchorageviatheSusitnadrainage.AllfouroftheseincorporatethesegmentthatrunsfromtheendpointsofPointMacKenzietoTalkeetna,sothissegmentcan,therefore,betreatedasseparateandnotincludedinacomparisonofthealternativecorridors.OfthefourcorridorsthatrunfromTalkeetnatoDevilCanyon-Watana,thefirstisthesouthernhalfoftheproposedcorridor,whichfollowstheSusitnavalleynorth,parallelingtheAlaskaRailroadtoGoldCreek,whereitasoleadseasttotieintoDevilCanyon-Watana(Susitna-1,inFigure5).fhenext,andfarthestwestparallelstheAnchorage-FairbanksHighwaythroughDenaliStatePark,alongTroublesomeCreek,eventuallyleadingeasttotieintoGoldCreekandDevilCanyon-Watana(Susitna-2).ThethirdgoesuptheTalkeetnaRiverandgainingtheridgetotheeastofDisappointmentCreek,leadsnorthtotheridgeleadingtoDevilCanyon(Susitna-3).ThefourthandmosteasterlycorridorfollowstheTalkeetnaRivertoPrairieCreek,whichitfollowstoStephanLake,halfwaybetweenDevilCanyonandWatana(Susitna-4).NenanaCorridorsTherearefivefeasiblecorridorsconnectingtheUpperSusitnawithFairbanksbywayoftheNenanaRiver.ThefirstisacorridorparallelingthehighwavandrailroadfromGoldCreektoCantwell,toHealy,andtoFairbanks.Thisisthenorthernhalfofthepreferredcorridor(Nenana-I,inFigure5).12THECORRIDORSThealternativesystemplansrepresentonlygeneralcorridors,anddonotattempttodefineanactualright-of-way.Thusthealternativesdonotdistinguishamongmanyminorvariations,andasaresult,arefairlyflexible.Therearefourgroupsofalternatives:first,thosethatleadfromDevilCanyon-WatanatoAnchorageviatheSusitnawatershed;second,thosethatleadtoFairbanksviatheNenanaandTananadrainage;third,thosethatleadtoFairbanksviatheDeltaandTananadrainages;andfourth,thosethatleadtoAnchorageviatheCopperandMatanuskadrainages(seeFigures4and5,andStripMapsinAppendixII).SusitnaCorridorsTherearebasicallyfourfeasiblec,.,.idorswhichconnectDevilCanyontoAnchorageviatheSusitnadrainage.AllfouroftheseincorporatethesegmentthatrunsfromtheendpointsofPointMacKenzietoTalkeetna,sothissegmentcan,therefore,betreatedasseparateandnotincludedinacomparisonofthealternativecorridors.OfthefourcorridorsthatrunfromTalkeetnatoDevilCanyon-Watana,thefirstisthesouthernhalfoftheproposedcorridor,whichfollowstheSusitnavalleynorth,parallelingtheAlaskaRailroadtoGoldCreek,whereitasoleadseasttotieintoDevilCanyon-Watana(Susitna-1,inFigure5).fhenext,andfarthestwestparallelstheAnchorage-FairbanksHighwaythroughDenaliStatePark,alongTroublesomeCreek,eventuallyleadingeasttotieintoGoldCreekandDevilCanyon-Watana(Susitna-2).ThethirdgoesuptheTalkeetnaRiverandgainingtheridgetotheeastofDisappointmentCreek,leadsnorthtotheridgeleadingtoDevilCanyon(Susitna-3).ThefourthandmosteasterlycorridorfollowstheTalkeetnaRivertoPrairieCreek,whichitfollowstoStephanLake,halfwaybetweenDevilCanyonandWatana(Susitna-4).NenanaCorridorsTherearefivefeasiblecorridorsconnectingtheUpperSusitnawithFairbanksbywayoftheNenanaRiver.ThefirstisacorridorparallelingthehighwavandrailroadfromGoldCreektoCantwell,toHealy,andtoFairbanks.Thisisthenorthernhalfofthepreferredcorridor(Nenana-I,inFigure5).12 Figure4230KVDoubleCircuitHealyNENANAICORRIDORCantwell./•FAIRBANKSDELTACORRIDOR230KVDoubleCircuit75100125~P.A.-Morch1975IIPaxson50DEVILCANYONPROJECTALTERNATIVESYSTEMPLANSScaleinmiles,j(,~.<,,,..__-il.UNITEDSTATESDEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATION!a~DenaliDevilCanyon;I'-...::J'-----'r'---",....'---JWO~iJrla"0Iee,13Figure4230KVDoubleCircuitHealyNENANAICORRIDORCantwell./•FAIRBANKSDELTACORRIDOR230KVDoubleCircuit75100125~P.A.-Morch1975IIPaxson50DEVILCANYONPROJECTALTERNATIVESYSTEMPLANSScaleinmiles,j(,~.<,,,..__-il.UNITEDSTATESDEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATION!a~DenaliDevilCanyon;I'-...::J'-----'r'---",....'---JWO~iJrla"0Iee,13 Figure5UNITEDSTATESDEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONDEVILCANYONPROJECTALTERNATIVETRANSMiSSiONCORRIDORSScaleinmiles100125A.P.A,March197575DELTACORRIDORMatonusko~250"'iOPOSED,.....14Figure5UNITEDSTATESDEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONDEVILCANYONPROJECTALTERNATIVETRANSMiSSiONCORRIDORSScaleinmiles100125A.P.A,March197575DELTACORRIDORMatonusko~250"'iOPOSED,.....14 ThesecondduplicatesthefirstcorridortoCantwell,butthenleadseastparallelingtheDenaliHighway,northupasfarasWellsCreekandoverthepasstoLouisCreek,continuingovertheDeanCreekPasstotheWoodRiver.ItthenfollowstheWoodandTananaRiverstoFairbanks(Nenana-2).Thethirdcorridor,(Nenana-3).duplicatesthesecondtoDeanCreek,whereitthencontinuesupYanertForkandoverMoodyPass,endingupatHealyandjoiningthefirstcorridor.Corridorfour(Nenana-4)leavesWatanaandheadsnorth.emergingontotheDenaliHighwayneartheBrushkanaRiver.Itthenleadswest,goesupWellsCreek.andjoinscorridorthreetoHealyandFairbanks.Corridorfivestartsthesamewayascorridorfour,exceptthatinsteadofgoingoverMoodyPasstoHealy,itleadseastoverDeanCreekintotheWoodRiver.andthenleadsnorthtoFairbanks.(Nenana-5).DeltaCorridorThereisonlyonebasicallyfeasiblecorridoralongtheDeltaRiver.ThiscorridorleavesWabnadamsiteandleadseastdownButteCreektotheDenalidamsiteandco"tinueseastalongtheDenaliHighway.Itthenproceedsnorthneal'PaxsonoverIsabelPassandparallelstheRichardsonHighwayintoFairbanks.1'v.tc:.l'anuskaCorridorsTherearetwocorridorsutilizingtheMatanuskaValleyasaccesstoAnchorage.ThefirstfollowstheDeltaroutetoPaxson,thenleadssouthtoGlennallen.Itthengoeswest,overTahnetaPass,andintotheMatanuskaValley,tyingintoPointMacKenzie.ThesecondcorridorconnectsWatanatoVeedamsite,leadssoutheasttotheLittleNelchinaRiver,whichitfollowstotheGlennHighwayandcorridorone,whichitfollowstoPointMacKenzie.Inordertomoreeasilyassessenvironmentalimpactsofatransmissionlineonthesecorridors,theyarereducedtosmallerunits.orcorridorsegments.Asegmentisthusthatpartofacorridor.eitherbetweentwointersectionswithothercorridors,orbetweenanintersectionandoneoftheendpointsnearAnchorageorFairbanks.Thelengthofasegment15ThesecondduplicatesthefirstcorridortoCantwell,butthenleadseastparallelingtheDenaliHighway,northupasfarasWellsCreekandoverthepasstoLouisCreek,continuingovertheDeanCreekPasstotheWoodRiver.ItthenfollowstheWoodandTananaRiverstoFairbanks(Nenana-2).Thethirdcorridor,(Nenana-3).duplicatesthesecondtoDeanCreek,whereitthencontinuesupYanertForkandoverMoodyPass,endingupatHealyandjoiningthefirstcorridor.Corridorfour(Nenana-4)leavesWatanaandheadsnorth.emergingontotheDenaliHighwayneartheBrushkanaRiver.Itthenleadswest,goesupWellsCreek.andjoinscorridorthreetoHealyandFairbanks.Corridorfivestartsthesamewayascorridorfour,exceptthatinsteadofgoingoverMoodyPasstoHealy,itleadseastoverDeanCreekintotheWoodRiver.andthenleadsnorthtoFairbanks.(Nenana-5).DeltaCorridorThereisonlyonebasicallyfeasiblecorridoralongtheDeltaRiver.ThiscorridorleavesWabnadamsiteandleadseastdownButteCreektotheDenalidamsiteandco"tinueseastalongtheDenaliHighway.Itthenproceedsnorthneal'PaxsonoverIsabelPassandparallelstheRichardsonHighwayintoFairbanks.1'v.tc:.l'anuskaCorridorsTherearetwocorridorsutilizingtheMatanuskaValleyasaccesstoAnchorage.ThefirstfollowstheDeltaroutetoPaxson,thenleadssouthtoGlennallen.Itthengoeswest,overTahnetaPass,andintotheMatanuskaValley,tyingintoPointMacKenzie.ThesecondcorridorconnectsWatanatoVeedamsite,leadssoutheasttotheLittleNelchinaRiver,whichitfollowstotheGlennHighwayandcorridorone,whichitfollowstoPointMacKenzie.Inordertomoreeasilyassessenvironmentalimpactsofatransmissionlineonthesecorridors,theyarereducedtosmallerunits.orcorridorsegments.Asegmentisthusthatpartofacorridor.eitherbetweentwointersectionswithothercorridors,orbetweenanintersectionandoneoftheendpointsnearAnchorageorFairbanks.Thelengthofasegment15 Figure675100125A.P.A.-Morch19758Paxson2150DEVILCANYONPROJECTTRANSMISSIONCORRIDORSEGMENTSScaleinmiles'i"'YjN'I'¢~DSTATESDEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONSlideMountain14scr~l.n_18'D.nO~2216Figure675100125A.P.A.-Morch19758Paxson2150DEVILCANYONPROJECTTRANSMISSIONCORRIDORSEGMENTSScaleinmiles'i"'YjN'I'¢~DSTATESDEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONSlideMountain14scr~l.n_18'D.nO~2216 isnotstandard,noristhelengthsetbyanyphysicalcriteria.Thesesegmentsaretheminimumnumberofunitsthatcanbecombinedtoformthepreviouslydescribedalternativecorridors(seeFigure6).Assessmentoftheexistingenvironmentandofimpactsofatransmissioncorridorwillbedoneonthesegmentlevel.Asaconvenience,theseassessmentswillbetabulatedonmatrixform,differentiatedastoenvironmentalinventoryandassessmentofimpacts.TheSusitnaandNenanacorridorswilleachhaveseparatematrixes;theMatanuskaandDeltacorridorswillbecombinedbecauseofthefewernumberofalternatives.Segmentsarelabelledintwoways;thefirstisanodallabel,inwhichthenodesidentifythesegment(e.g.WellsCreek-DeanCreek),thesecondisanassignednumberwhichcorrespondstoakeymap.Bothlabelsareusedonthematrix.Matrixeswillbefoundonpp.18-20andpp.33-35.ENVIRONMENTALASSESSMENTOFCORRIDORS17isnotstandard,noristhelengthsetbyanyphysicalcriteria.Thesesegmentsaretheminimumnumberofunitsthatcanbecombinedtoformthepreviouslydescribedalternativecorridors(seeFigure6).Assessmentoftheexistingenvironmentandofimpactsofatransmissioncorridorwillbedoneonthesegmentlevel.Asaconvenience,theseassessmentswillbetabulatedonmatrixform,differentiatedastoenvironmentalinventoryandassessmentofimpacts.TheSusitnaandNenanacorridorswilleachhaveseparatematrixes;theMatanuskaandDeltacorridorswillbecombinedbecauseofthefewernumberofalternatives.Segmentsarelabelledintwoways;thefirstisanodallabel,inwhichthenodesidentifythesegment(e.g.WellsCreek-DeanCreek),thesecondisanassignednumberwhichcorrespondstoakeymap.Bothlabelsareusedonthematrix.Matrixeswillbefoundonpp.18-20andpp.33-35.ENVIRONMENTALASSESSMENTOFCORRIDORS17 MatrixesforInventoryofCorridorSegments:Thefollowingmatrixesareforinventoryoftheenvironmentbyninecategories.ThedefinitionsofthecategoriesandgeneralinformationaregivenintheAppendixI.Theprocessfromwhichthe22corridorsegmentsarederivedisexplainedonpages10-15.Duetofueproblemsattendanttoreducingsuchlargeamountsofinformationtosuchaconstrainedformat,itwouldappearfuatsomeofthecategoriesarenottreatedOnfuesamelevelofdetailasothers.Specifically,climate,whichisaless-studiedandlessstablesituationthansoils,whicharetreatedonamoredetailedlevel.Onlydatathatwasfoundbysearchingfueliteraturewasentered.Thus,forexample,cariboumaybefoundinasegmentalfuoughnomentionofitismadeinthematrix.Oneadvantagetothematrixsystemofpresentationisthatl';Seasilyupdated;thus.descrepmciesbroughttoourattentioncaneasilybechanged.Theconstraintsoffuisformatalsoobligetheuseofabreviations;MMCPMzonestandsfortheMountMcKinelyCooperativePlanningandManagementzone,GVEAleferstotheGoldenValleyElectricAssocia-tion,MEAreferstotheMe.tanuskaElectricAssociation,andtheARRisfueAlaskaRailroad.'IJclandstatusentriesarebaseduponthelandstatussituationof"rch1974.Stateselectionsrefertonotonlypatented,butalsoallpendingandtentativelyapprovedStateselections.Nativevillagedeficienciesandregionaldeficiencies(NVDandNRD)willperhapsbefuemostunstableareasatpresent,soitisquitelikelythattheentriesregardingtheselandsmaynotbepresentlyvalid.19MatrixesforInventoryofCorridorSegments:Thefollowingmatrixesareforinventoryoftheenvironmentbyninecategories.ThedefinitionsofthecategoriesandgeneralinformationaregivenintheAppendixI.Theprocessfromwhichthe22corridorsegmentsarederivedisexplainedonpages10-15.Duetofueproblemsattendanttoreducingsuchlargeamountsofinformationtosuchaconstrainedformat,itwouldappearfuatsomeofthecategoriesarenottreatedOnfuesamelevelofdetailasothers.Specifically,climate,whichisaless-studiedandlessstablesituationthansoils,whicharetreatedonamoredetailedlevel.Onlydatathatwasfoundbysearchingfueliteraturewasentered.Thus,forexample,cariboumaybefoundinasegmentalfuoughnomentionofitismadeinthematrix.Oneadvantagetothematrixsystemofpresentationisthatl';Seasilyupdated;thus.descrepmciesbroughttoourattentioncaneasilybechanged.Theconstraintsoffuisformatalsoobligetheuseofabreviations;MMCPMzonestandsfortheMountMcKinelyCooperativePlanningandManagementzone,GVEAleferstotheGoldenValleyElectricAssocia-tion,MEAreferstotheMe.tanuskaElectricAssociation,andtheARRisfueAlaskaRailroad.'IJclandstatusentriesarebaseduponthelandstatussituationof"rch1974.Stateselectionsrefertonotonlypatented,butalsoallpendingandtentativelyapprovedStateselections.Nativevillagedeficienciesandregionaldeficiencies(NVDandNRD)willperhapsbefuemostunstableareasatpresent,soitisquitelikelythattheentriesregardingtheselandsmaynotbepresentlyvalid.19 SUSITNACORRIDORSINVENTORYCLIMATEEXISTINGDEVELOPMENTSLANDOWNERSHIP/STATUSEXISTINGRIGHTS-OF-WAYSCENICQUALITY/RECREATIONVarioussmalltownsalongtrans~PrimarilyStatepotentialsel-Recreationareas:BigLake,Rocky~ar"Transitional-milderandwetterportationcorridor.Severalections;indetenninate(asofAnchorage~FairbanksHighway,Lake(SUckerLake),NancyLake,insouthernendofsegment.recreationareasandcarrpgrotmds3 -74)NativevillagesofMontanaAlaskaRa~lroad,MEAlines.WillowCreek.Mediumtolowalonghighway.Creek,Caswell,andWk.scenicqualityinsouth.MediumtohigharotmdTalkeetna.)lackTransitional/rnotmtain.Stateselectedland.DenaliStateParallelsAnchorage-FairbanksRtm.sthroughDenaliStatePark.,?\'one.Highscenicquality,penetratesPark.Highwayinmidsection.DenaliStatePark.Transitional.TownsofGoldCreek,Curry,LaneStateselectedland,borderson'ParalleleastbotmdaryDenalirers.Chase,and Shennan(railroadDenaliStatePark.ParallelsA.R.R.StatePark.stops).arers.Transitional.Stateselectedland.None.!>1ediumscenicvalue.relativelyNone.accessiblebyboat.Id--'1/3,State:electedland,2/3~izzly~IDuntain/transitional.None.Highscenicqualityarea-rela--.Nahvereg~onaldeficiency.None.tivelyinaccessible.ears.li3.Stateselectedland,2/3Somerecreationaluseoflakesin~IDuntain/transitional.None.Na~~veregionaldeficiency.None.PrairieCreekPassarea.Highscenicquality-accessiblebyfloatplane.1/2Stateselections~ghscenicquality-impressiveNone.1/2NativeNone.r:v~rvalley.Limitedaccessi-Transitional.regionaldeficiency.'blhty.~ar,,~buntain/transitional.Nativeregionaldeficiency,po\."er~Highscenicquality-limited,None.sitewithdral'lalforDenaliCanyonNone.accessibility.Reservoir.ear,l>buntain.Nativeregionaldeficiency,power-RecreationaluseofFogLakesNone.None.area.Highscenicquality-sitewithdrawalforDenaliCanyonaccessiblebyfloatplane.Reservoir.20SUSITNAINVENTORYSUSITNACORRIDORSINVENTORYCLIMATEEXISTINGDEVELOPMENTSLANDOWNERSHIP/STATUSEXISTINGRIGHTS-OF-WAYSCENICQUALITY/RECREATIONVarioussmalltownsalongtrans~PrimarilyStatepotentialsel-Recreationareas:BigLake,Rocky~ar"Transitional-milderandwetterportationcorridor.Severalections;indetenninate(asofAnchorage~FairbanksHighway,Lake(SUckerLake),NancyLake,insouthernendofsegment.recreationareasandcarrpgrotmds3-74)NativevillagesofMontanaAlaskaRa~lroad,MEAlines.WillowCreek.Mediumtolowalonghighway.Creek,Caswell,andWk.scenicqualityinsouth.MediumtohigharotmdTalkeetna.)lackTransitional/rnotmtain.Stateselectedland.DenaliStateParallelsAnchorage-FairbanksRtm.sthroughDenaliStatePark.,?\'one.Highscenicquality,penetratesPark.Highwayinmidsection.DenaliStatePark.Transitional.TownsofGoldCreek,Curry,LaneStateselectedland,borderson'ParalleleastbotmdaryDenalirers.Chase,and Shennan(railroadDenaliStatePark.ParallelsA.R.R.StatePark.stops).arers.Transitional.Stateselectedland.None.!>1ediumscenicvalue.relativelyNone.accessiblebyboat.Id--'1/3,State:electedland,2/3~izzly~IDuntain/transitional.None.Highscenicqualityarea-rela--.Nahvereg~onaldeficiency.None.tivelyinaccessible.ears.li3.Stateselectedland,2/3Somerecreationaluseoflakesin~IDuntain/transitional.None.Na~~veregionaldeficiency.None.PrairieCreekPassarea.Highscenicquality-accessiblebyfloatplane.1/2Stateselections~ghscenicquality-impressiveNone.1/2NativeNone.r:v~rvalley.Limitedaccessi-Transitional.regionaldeficiency.'blhty.~ar,,~buntain/transitional.Nativeregionaldeficiency,po\."er~Highscenicquality-limited,None.sitewithdral'lalforDenaliCanyonNone.accessibility.Reservoir.ear,l>buntain.Nativeregionaldeficiency,power-RecreationaluseofFogLakesNone.None.area.Highscenicquality-sitewithdrawalforDenaliCanyonaccessiblebyfloatplane.Reservoir.20SUSITNAINVENTORY PointMacKenzie-TalkeetnaTOPOGRAPHY/GEOLOGY84miles.Highestpoint500'atTalkeetnatosealevelatPt.McKenzie.Widerivervalley;eastbankmorerollingthanex-tremelyflatwestbank.Valleywidensandflattenstosouth.Poorlydrained.manybogsandlakes.'SOILSGlacialdebris-groundmor~inealteredbyoutwash.floodplains,silt.sand.gravel.swartpsandlakes.Discontinwuspennafrost.Poorly-drainedfibrouspeatsoils.,vulnerabletofrostheavingandwell-drainedstronglyacidsoils.LCMtomediunerosionpotential.VEGETATIONBottomlandspruce-poplar,lowland'spruce-hardwood.muskeg/bog.WILDLIFEl'-boseeverywhere,blackbear"furbearers.SUSITNAeLlTransitional-insouthernenTalkeetna-GoldCreekviaTroublesomeCreek(2)42miles.Rollinghighplateautonorth.becomingflatter,lower.forestedhillstosouth.MergesintoSusitnaValley.Highpointaround2000'.Innorthernpart,welldrainedthinsoils,stronglyacid;deeppennafrosttable.SouthernpartBottomlandspruce-poplar.uplandpoorlydrainedfibrouspeat.vul=spruce-hardwood,lowblUSh,mus-nerab1etoheavingandwelldrained'kegjbog.Alpinetlmdra(?).stronglyacidsoils.Slopesonnorth>12%.Lowtomediumerosionpotential.Cariboumightbepresent,blackbear.moose.Transition38miles.Highpoint900'.VeeT~lkeetna,-G?ldCreekCanyon-moderatelynarrowvalleyVlaAlaskaRaIlroad(3)Ifl?orwideningtothesouth.Welldrained.gravelly.strongly"acidsoils.Southernthird,poorly,drained.fibrouspeatandwelldrained.stronglyacidsoil.SlopesOnnorth}12%.Lowtomediumerosionpotential..-'Bottomlandspruce-poplar.,spruce-hardwood.upland,l'-bose.blackbear.furbearers.TransitiTalkeetnaRiver(4)DisappointmentCreek,(5),PrairieCreek-StephanLake(6)DevilCanyon-Gold'Cr~ek(7)DevilCanyon-Stephan,Lake(8)StephanLake-Watana(9)8miles.500'elevation.WideWllingvalleybottom.Manylakes.37miles.3800'elevation.Rollinghillsincreaseineleva-tiontohighplateauwithseveralincisedcreeks.•:42miles.2200'elevation.Widevalleynarrowsgraduallyasitrisestowide.flat.poorlydraine~pass.14miles.1500'elevationabovedamsite.Narrowcanyonincised.inplateauwidensasplateau.changestorollinghillstowest.'13miles.2200'elevation.Highplateauwithdeeplymcisedcreeksandrivers.17miles.2200'elevation.Flatplateauboundedbyhillstonorthandsouth,incisedriverandcreeksPoorlydrainedfibrouspeat.vulnerabletoheavitlgandwelldrained,stronglyacidsoils.Slopes<12%.Lowtomediumerosionpotential.WelldraiDed.stronglyacidsoilsthininnorthernpartsincon'"jmctionwithverysteepandrockygromd.Gravellysoil.Slopes>12%.Lowerosionpote.nti~l.Welldrained.stronglyacid.gravellysoils.Slopes>12%.LowtomediumerosionP?tential.Welldrained,stronglyacid.'gravellysoils.Slopes>12%.Lowtomediumerosionpotential.Welldrained.stronglyacid.gravellysoils.Slopes>12%.Lowtomediumerosionpotential.Welldrained.thin,stronglyacidsoilswithdeeppennafrosttableandpoorlydrainedsoilswith'shallowtodeeppermafrosttable.Gravellysoils.Slopes<12%.Mediumerosion~otential.Bottomlandspruce-poplar.BotU;~andspruce-poplar.upland.spruce-hardwood,lowbrush.mus-'keg/bogandalpinetmdra.BottoTll1andspruce-poplar.uplandspruce-hardwood.lowbrushmus-keg/bogi~passarea.'Uplandspruce-hardwood.'·Uplandspruce-hardwoodinriver',andstreamvalleys.lowbrushandbog/muskegonplateaus.Uplandspruce-hardwoodinriveTandcreeks,blUShandbogandmus-k~gonplateau.,-l'-bose.blackbear.furbearers.l'-boseinlowerelevationsandstreambottoms.blackandgrizzlybear.possiblecaribourange.~bose.blackandgrizzlybears.Moose,blackbear.l'-bose,blackandgrizzlybear.Ifurbearers.l'-bose.blackandgriZZlybearfurbearers,caribou.'TransitiMountain/tl>fountain/tl}'btmtain/t'r.bunt2PointMacKenzie-TalkeetnaTOPOGRAPHY/GEOLOGY84miles.Highestpoint500'atTalkeetnatosealevelatPt.McKenzie.WiderivervalleYieastbankmorerollingthanex-tremelyflatwestbank.Valleywidensandflattenstosouth.Poorlydrained.manybogsandlakes.'SOILSGlacialdebris-groundmor~inealteredbyoutwash.floodplains,silt.sand.gravel.swartpsandlakes.Discontinwuspennafrost.Poorly-drainedfibrouspeatsoils.,vulnerabletofrostheavingandwell-drainedstronglyacidsoils.LCMtomediunerosionpotential.VEGETATIONBottomlandspruce-poplar,lowland'spruce-hardwood.muskeg/bog.WILDLIFEl-boseeverywhere,blackbear"furbearers.SUSITNAeLlTransitional-insouthernenTalkeetna-GoldCreekviaTroublesomeCreek(2)42miles.Rollinghighplateautonorth.becomingflatter,lower.forestedhillstosouth.MergesintoSusitnaValley.Highpointaround2000'.Innorthernpart,welldrainedthinsoils,stronglyacid;deeppennafrosttable.SouthernpartBottomlandspruce-poplar.uplandpoorlydrainedfibrouspeat.vul=spruce-hardwood,lowblUSh,mus-nerab1etoheavingandwelldrained'kegjbog.Alpinetlmdra(?).stronglyacidsoils.Slopesonnorth>12%.Lowtomediumerosionpotential.Cariboumightbepresent,blackbear.moose.Transition38miles.Highpoint900'.VeeT~lkeetna,-G?ldCreekCanyon-moderatelynarrowvalleyVlaAlaskaRaIlroad(3)Ifl?orwideningtothesouth.Welldrained.gravelly.strongly"acidsoils.Southernthird,poorly,drained.fibrouspeatandwelldrained.stronglyacidsoil.SlopesOnnorth}12%.Lowtomediumerosionpotential..-'Bottomlandspruce-poplar.,spruce-hardwood.upland,l-bose.blackbear.furbearers.TransitiTalkeetnaRiver(4)DisappointmentCreek,(5),PrairieCreek-StephanLake(6)DevilCanyon-Gold'Cr~ek(7)DevilCanyon-Stephan,Lake(8)StephanLake-Watana(9)8miles.500'elevation.WideWllingvalleybottom.Manylakes.37miles.3800'elevation.Rollinghillsincreaseineleva-tiontohighplateauwithseveralincisedcreeks.•:42miles.2200'elevation.Widevalleynarrowsgraduallyasitrisestowide.flat.poorlydraine~pass.14miles.1500'elevationabovedamsite.Narrowcanyonincised.inplateauwidensasplateau.changestorollinghillstowest.'13miles.2200'elevation.Highplateauwithdeeplymcisedcreeksandrivers.17miles.2200'elevation.Flatplateauboundedbyhillstonorthandsouth,incisedriverandcreeksPoorlydrainedfibrouspeat.vulnerabletoheavitlgandwelldrained,stronglyacidsoils.Slopes<12%.Lowtomediumerosionpotential.WelldraiDed.stronglyacidsoilsthininnorthernpartsincon'"jmctionwithverysteepandrockygromd.Gravellysoil.Slopes>12%.Lowerosionpote.nti~l.Welldrained.stronglyacid.gravellysoils.Slopes>12%.LowtomediumerosionP?tential.Welldrained,stronglyacid.'gravellysoils.Slopes>12%.Lowtomediumerosionpotential.Welldrained.stronglyacid.gravellysoils.Slopes>12%.Lowtomediumerosionpotential.Welldrained.thin,stronglyacidsoilswithdeeppennafrosttableandpoorlydrainedsoilswith'shallowtodeeppermafrosttable.Gravellysoils.Slopes<12%.Mediumerosion~otential.Bottomlandspruce-poplar.BotU;~andspruce-poplar.upland.spruce-hardwood,lowbrush.mus-'keg/bogandalpinetmdra.BottoTll1andspruce-poplar.uplandspruce-hardwood.lowbrushmus-keg/bogi~passarea.'Uplandspruce-hardwood.'·Uplandspruce-hardwoodinriver',andstreamvalleys.lowbrushandbog/muskegonplateaus.Uplandspruce-hardwoodinriveTandcreeks,blUShandbogandmus-k~gonplateau.,-l-bose.blackbear.furbearers.l-boseinlowerelevationsandstreambottoms.blackandgrizzlybear.possiblecaribourange.~bose.blackandgrizzlybears.Moose,blackbear.l-bose,blackandgrizzlybear.Ifurbearers.l-bose.blackandgriZZlybearfurbearers,caribou.'TransitiMountain/tl>fountain/tl!'-btmtain/t'r.bunt2 WILDLIFENENANACORRIDORSINVENTORYCLIMATE"EXISTINGDEVELOPMENTSLANDOWNERSHIP/STATUSEXISTINGRIGHTS-OF-WAYSCENICQUALITY/RECREATIONespeciallyinlowerMOuntain/transition.Sunmitweath-Severalsmallcommunities'alongI.High~cenicqualityalongmos~ofar.up-lIbosepresent,..thisroute.southernpartbordersbrush-valleys,blackbearonforesteder:annualtemperature25.9F••transportationlines.FAAstripsStateselectedland,Nativevillage,An~horage-FairbanksHighway,AlaskaDenaliStatePark.Majorviewstoareas.annualprecipitation21.85".atSummi.tandCantwell.Southern\.;ithdrawal.areawithin/l-f.K:P/llZone.Ra~lroad.westandnorthoftransportationpartbordersDenaliStatePark.corridorofAlaskaRange..'landCaribouconcentrations,moosein'Neditunscenicqualitybutinacces-lowervalleysandplateaus.DallMotmtain.None.D-lwithdrawal.northernpartwithNone.sible.-muskegsheepinhighareas,blackbearonin!lNCFNZone.forestedareas.mod.Caribouconcentrations.moosepre-DenahHighway.settlementNativevillagewithdrawal.StateDenaliHighway.Highscenicqualitygoodviewstosent,Dallsheepinhighareas,1I1otmtain.someallsides.•blackbearinforestedarea.alonghighway.selectedland.withinlIf.mfZone.Motmtain.HighwindsreportedbySeveralsmallcommunities.lIlc-lm.;landCaribouconcentrationssouthofGVEAtohaveknockeddown138KVKinleyParkonwestbankofNenanaStateselectedlandandlIlcKinleyHighscenicquality.impressivettmdra,canyons,moosepresentinmoretowers.McKinleyweather:annualRiver.FlightstripsofYanertAnchorage-FairbanksH1ghway.Alaskacanyonsinterspersedwithopenkeg.openpartsofcanyons.Dallsheeptemperature27.7F.,annualprecip-and/l-lcKinleyVillageandHealyNationalPark,withinlIf>lCP/lIZone.·Railroad.areasofmoredistantviews.Goodinhighareas,blackbear'present.itation14.SO".(FMatMcKinley).possibilityofviewingwildlife.Hightouristtrade.llandCaribouconcentrations,moosein'muskeg/lowerelevations.DallsheepinlIlolUltain.None.D-IandStateselectedland,WellsNone.Highscenicqualitybutinacces-19hbrushhighareas,blackbearinforestedCreekwithinM!llCP/lIZone.sible.area,¥Tizzlybearin,higherareas.plandCaribouconcentrations.moosein-mus-lOIl'erelevations,DallsheepinMotmtain.NoneinmOtmtainsjUsibelliCoalMediwnscenicqualitybutinacces-pinehighareas,blackbearinforestedMinesatHealy.Stateselectedland.None.sible.Hoodyareas.grizzlybearinhigherareas...uplandCaribouconcentrationsonwest;pruce-bankofNenanabetweenHealyandSmallcommunitiesalongtransporta-PrimarilyStateselected"land,'lithHighscenicqualitynearHealyand,eg/bog,southofClearAFB.moosealongInterior.Healyweather:annualtionlines.Severalflightstrips.someexistingfederalwithdrawalsAn~horage-FairbanksHighway,AlaskatheGoldstreamHills.Lowtomed-northwholeroute,blackbearinfor-temperature26.4°F.,annualpre-FMstationatNenana.Tmmof'andNativevillagewithdr8\~als.Ra~lroad,GVEA138lev.line.hunscenicqualityalonglower·hard-estedareas.cipitation11.34"Nenana,Clear!lfilitaryReservation~.,NenanaRiver.DryCreekArcheo-.andlogicalSite[NationalRegister).lowCaribouconcentrationsinupperttmdra,WoodRiver,moosepresentinlowerPriJ;taril~Stateselectedland.None..Scenicqualityrangesfromhigh)l.;erelevationsandstreambottoms,DallMountain,mostpartinterior.BlairLakelItilitaryReservation.Na~1~VJ..llagedeficiencyandtomediumbutinaccessible.tspersedsheeponhighareasofupperWoodenstmgFederalwithdrawals.withRiver,blackandgrizzlybearpre-ltterns.sent.21NENANAINVENTORYWILDLIFENENANACORRIDORSINVENTORYCLIMATE"EXISTINGDEVELOPMENTSLANDOWNERSHIP/STATUSEXISTINGRIGHTS-OF-WAYSCENICQUALITY/RECREATIONespeciallyinlowerMOuntain/transition.Sunmitweath-Severalsmallcommunities'alongI.High~cenicqualityalongmos~ofar.up-lIbosepresent,..thisroute.southernpartbordersbrush-valleys,blackbearonforesteder:annualtemperature25.9F••transportationlines.FAAstripsStateselectedland,Nativevillage,An~horage-FairbanksHighway,AlaskaDenaliStatePark.Majorviewstoareas.annualprecipitation21.85".atSummi.tandCantwell.Southern\.;ithdrawal.areawithin/l-f.K:P/llZone.Ra~lroad.westandnorthoftransportationpartbordersDenaliStatePark.corridorofAlaskaRange..'landCaribouconcentrations,moosein'Neditunscenicqualitybutinacces-lowervalleysandplateaus.DallMotmtain.None.D-lwithdrawal.northernpartwithNone.sible.-muskegsheepinhighareas,blackbearonin!lNCFNZone.forestedareas.mod.Caribouconcentrations.moosepre-DenahHighway.settlementNativevillagewithdrawal.StateDenaliHighway.Highscenicqualitygoodviewstosent,Dallsheepinhighareas,1I1otmtain.someallsides.•blackbearinforestedarea.alonghighway.selectedland.withinlIf.mfZone.Motmtain.HighwindsreportedbySeveralsmallcommunities.lIlc-lm.;landCaribouconcentrationssouthofGVEAtohaveknockeddown138KVKinleyParkonwestbankofNenanaStateselectedlandandlIlcKinleyHighscenicquality.impressivettmdra,canyons,moosepresentinmoretowers.McKinleyweather:annualRiver.FlightstripsofYanertAnchorage-FairbanksH1ghway.Alaskacanyonsinterspersedwithopenkeg.openpartsofcanyons.Dallsheeptemperature27.7F.,annualprecip-and/l-lcKinleyVillageandHealyNationalPark,withinlIf>lCP/lIZone.·Railroad.areasofmoredistantviews.Goodinhighareas,blackbear'present.itation14.SO".(FMatMcKinley).possibilityofviewingwildlife.Hightouristtrade.llandCaribouconcentrations,moosein'muskeg/lowerelevations.DallsheepinlIlolUltain.None.D-IandStateselectedland,WellsNone.Highscenicqualitybutinacces-19hbrushhighareas,blackbearinforestedCreekwithinM!llCP/lIZone.sible.area,¥Tizzlybearin,higherareas.plandCaribouconcentrations.moosein-mus-lOIl'erelevations,DallsheepinMotmtain.NoneinmOtmtainsjUsibelliCoalMediwnscenicqualitybutinacces-pinehighareas,blackbearinforestedMinesatHealy.Stateselectedland.None.sible.Hoodyareas.grizzlybearinhigherareas...uplandCaribouconcentrationsonwest;pruce-bankofNenanabetweenHealyandSmallcommunitiesalongtransporta-PrimarilyStateselected"land,'lithHighscenicqualitynearHealyand,eg/bog,southofClearAFB.moosealongInterior.Healyweather:annualtionlines.Severalflightstrips.someexistingfederalwithdrawalsAn~horage-FairbanksHighway,AlaskatheGoldstreamHills.Lowtomed-northwholeroute,blackbearinfor-temperature26.4°F.,annualpre-FMstationatNenana.Tmmof'andNativevillagewithdr8\~als.Ra~lroad,GVEA138lev.line.hunscenicqualityalonglower·hard-estedareas.cipitation11.34"Nenana,Clear!lfilitaryReservation~.,NenanaRiver.DryCreekArcheo-.andlogicalSite(NationalRegister).lowCaribouconcentrationsinupperttmdra,WoodRiver,moosepresentinlowerPriJ;taril~Stateselectedland.None..Scenicqualityrangesfromhigh)l.;erelevationsandstreambottoms,DallMountain,mostpartinterior.BlairLakelItilitaryReservation.Na~1~VJ..llagedeficiencyandtomediumbutinaccessible.tspersedsheeponhighareasofupperWoodenstmgFederalwithdrawals.withRiver,blackandgrizzlybearpre-ltterns.sent.21NENANAINVENTORY NENANACORRIDORSINVENTORYTOPOGRAPHY/GEOLOGYSOILSVEGETATIONWILDLIFECLIMATEEXIS'GoldCreek-Cantwell(10)62miles.2400'elevation.Wide'valleywithmoderatelyincisedriversinsouth,becomingverywidedepressioninBroadPass,travelingNE,withrollingval-leybottom.Welldra:i.TI.ed,thin,stronglyacidsoils,deeppennafrosttableandpoorlydrainedwithsurfacepeatandshallowpennafrosttable.Bothsoilsgravellywithmediumerosionpotential.Slopes<12%.Bottomlandspruceandpoplar,up-landspruce-hardwood,lowbrush-bog/muskeg.~bosepresent,especiallyinlowerMOuntain/transition.Summitweath-valleys,blackbearonforesteder:armualtemperature25.9F.,areas.annualprecipitation21.85".Several:transporatSwmm:partborlIWatana-WellsCreekv.;i.aBrushkanaCreek(11)46miles.3300'atDeadmanPass.Seriesofmoderatelywidevalleysjoinedbygentlepasses,culminat-ingonwidevalleyofBrushkanaCreekandNenanaRiver.Onslopes>12%:Welldrainedthinstronglyacidsoilswithdeepper-mafrosttable,grav~l1y.Onsl0J;!esUplandspruce-hardwood,lowland<12%:Poorlydramedloamys01.lsspruce-hardl\'oodlowbrush-muskegwithsurfacepeatandshallOll'per-bog.Alpinet~dramafrosttable.Mediumerosionpo-..tential.Caribouconcentrations,mooseinlowervalleysandplateaus,Dallsheepinhighareas,blackbearonforestedareas.l>buntain.WellsCreek-Cantwell(12)Cantwell-Healy(13).~Welldrained,thin,stronglyacid22nules.2500I _elevation.Valleysoilswithdeeppennafrosttable~tWellsCreekmdenstowest,withinconjmctionlI'ithpoorlydrained.~atbottombomdbymomtainstosoilswithsurfacepeatandshallow·northandsouth.pennafrosttable.Mediumerosionpotential.Gravellysoils.Slopes<12%.39miles.2200'atCant""ell.Widevalleynarrowstonorthtoseri:s,We~ld:ained.nona<;idb:OlvngraveloftightcanyonsseparatedbyWl.des01.lsmconJunctlon""HhpoorlyvalleyofYamertFork.NorthofdrainedloamysoillI'ithsurfacecanyontoHealyiswideroll~gp:atand~hallo""pe:ma:Eros~table.'plainwithstreamterracesadJacenH1.~herOS1.onpotent1.al.ThmrockytoNenana.DenalifaultcrossesaSOl-Isandrockonlo""ercanyon..Windy..Lowlandspruce-hardwood.Uplandspruce-hardwood,10ll'landspruce-har<h.,rood,alpinetundra,some10""brush-bog/muskeg.Caribouconcentrations,moosepre-sent,Dansheepinhighareas,blackbearinforestedarea.Caribouconcentrationssouthofcanyons,moosepresentinmoreopenpartsofcanyons,Dallsheepinhighareas,blackbearpresent.Moto1tain.Moto1tain.HighwindsreportedbyGVEAtohave}mockeddown138KVtowers.McKinleyweather:annualtemperature27.7F.,annualprecip-itation14.50".DenalialonghSeveralKinleyfRiver.andMcKj(FAAatWellsCreek-DeanCreek(14)26miles.4,000'atWellsPass.WidevalleynarrowingtothenorthtopasswithLouisCreek,ahighsaddle.AbruptdropintoLouisCreek,downtoYanertForkandextremelywideaggradingchannel.Thinsoilsandrock,verysteepslopes.Levelareaspoorlydrained.Lowlandspruce-hardwood,uplandspruce-hardwood,lowbrush-nruskeg/bog,andalpinettmdra.HighbrushinYanertValley.Caribouconcentrations,mooseinlowerelevations,Dallsheepinhighareas,blackbearinforestedarea,?Tizzlybearin.higherareas.Mountain.DeanCreek-Healy(5)HealytoEster(16)Thinrockysoilsandrock,steep24;Ules.27001atMoodyPass.slopesonupperparts.Steep.Northupwidevalleyandoverll'idegravellypoorlydrainedsoilswithflatpassintosinuousv-canyon,:rariaJ:>lep:nnafrosttableincon-droppingintowidervalleyofHealyJto1ctl.onWIthsteepgravelly""ellCreek.~drainedgraysoils,shallo""bed-rock.Moderateerosionpotential.97miles.1400'atHealy.3501atHealy-Ne~:Well-drained.brownNenana,15001inGoldstreamHills.gravel:01.1sandpoorlydramedWide,terracedvalleyofNenanaloamsWI.thsmfacepeat,shall~flowsnorthtomergewithTanana.permafro:ttable.Nenana-~ster.floodplain.OverTananaRiver""ell-drame~brownloamsw1.th.trendingN.E.arelowrollinghillslenses~ffmesandpoorlydramedActivefaultatHealy.Ice-richloamsW1.thsmfacepea~,shallc;wclayandsiltatl>bo.dy.pe~frosttab~e.MediumtohIghLoIl'landspruce-hardwood,uplandspruce-har<h,;,ood,1011'brush-mus-keg/bog(inpassarea),alpinetto1dra(ridgesalonglo""erMoodyCre~k).Bottomlandspruce-poplar,upland·spruce-har<hl'ood,lowlandspruce-hardwood,10'1';'brush-muskeg/bog,levelareastendtobogs,northslopesarelowlandspruce-hard-.",'ood,swmyslopesareuplandspruce-hard""ood.Caribouconcentrations,mooseinlowerelevations,Dallsheepinhighareas,blackbearinforestedareas,grizzlybearinhigherareas.CaribouconcentrationsonwestbankofNenanabetweenHealyandsouthofClearAFB,moosealongwholeroute,blackbearinfor-estedareas.Mountain.Interior.Healyweather:annualtemperature26.4"F.,armualpre~cipitation11.34"NoneinMinesatSmallcottionlimFAAstatiNenana,(DeanCreektoEster(WoodP.iver)(17)110miles.43001atDean-NoodPasstJpperWoodRiver:ThinrockysoilsDeanCreek,sharpmotmtainvalleyLo""erWoodRiver:Poorlydrainedl).eadsinhighpassintoWoodRiver,loamysoils'dthsurfacepeatandau-shapedglaciervalleyll'ithag-shallo""pennafrosttable.Shallowgradingstream.lI'11icheventuallyslopes.SomewelldrainedbrmmdebouchesontoTananafloodplain,nonacidsoils.Loll'tomediumero-.:patandpoorlydrained.sionpotential.AIpinettmdra,highbrush,lowCaribouconcentrationsinupperbrushbogandmuskeg,moisttmdra,WoodRiver,moosepresentinlowerIrO'll'lan~spT1;1ce-hard""oo~,lOI\'erelevationsandstreambottoms,Dalli\oodRiverl.SareaofmterspersedsheeponhighareasofupperWoodbogsandleveesandmotmdsldthRiver,blackandgrizzlybearpre-correspondingvegetat~vepatterns.sent.MOlmtain.mostpartinterior.BlairLNENANACORRIDORSINVENTORYTOPOGRAPHY/GEOLOGYSOILSVEGETATIONWILDLIFECLIMATEEXIS'GoldCreek-Cantwell(10)62miles.2400'elevation.Wide'valleywithmoderatelyincisedriversinsouth,becomingverywidedepressioninBroadPass,travelingNE,withrollingval-leybottom.Welldra:i.TI.ed,thin,stronglyacidsoils,deeppennafrosttableandpoorlydrainedwithsurfacepeatandshallowpennafrosttable.Bothsoilsgravellywithmediumerosionpotential.Slopes<12%.Bottomlandspruceandpoplar,up-landspruce-hardwood,lowbrush-bog/muskeg.~bosepresent,especiallyinlowerMOuntain/transition.Summitweath-valleys,blackbearonforesteder:armualtemperature25.9F.,areas.annualprecipitation21.85".Several:transporatSwmm:partborlIWatana-WellsCreekv.;i.aBrushkanaCreek(11)46miles.3300'atDeadmanPass.Seriesofmoderatelywidevalleysjoinedbygentlepasses,culminat-ingonwidevalleyofBrushkanaCreekandNenanaRiver.Onslopes>12%:Welldrainedthinstronglyacidsoilswithdeepper-mafrosttable,grav~l1y.Onsl0J;!esUplandspruce-hardwood,lowland<12%:Poorlydramedloamys01.lsspruce-hardl\'oodlowbrush-muskegwithsurfacepeatandshallOll'per-bog.Alpinet~dramafrosttable.Mediumerosionpo-..tential.Caribouconcentrations,mooseinlowervalleysandplateaus,Dallsheepinhighareas,blackbearonforestedareas.l>buntain.WellsCreek-Cantwell(12)Cantwell-Healy(13).~Welldrained,thin,stronglyacid22nules.2500I _elevation.Valleysoilswithdeeppennafrosttable~tWellsCreekmdenstowest,withinconjmctionlI'ithpoorlydrained.~atbottombomdbymomtainstosoilswithsurfacepeatandshallow·northandsouth.pennafrosttable.Mediumerosionpotential.Gravellysoils.Slopes<12%.39miles.2200'atCant""ell.Widevalleynarrowstonorthtoseri:s,We~ld:ained.nona<;idb:OlvngraveloftightcanyonsseparatedbyWl.des01.lsmconJunctlon""HhpoorlyvalleyofYamertFork.NorthofdrainedloamysoillI'ithsurfacecanyontoHealyiswideroll~gp:atand~hallo""pe:ma:Eros~table.'plainwithstreamterracesadJacenH1.~herOS1.onpotent1.al.ThmrockytoNenana.DenalifaultcrossesaSOl-Isandrockonlo""ercanyon..Windy..Lowlandspruce-hardwood.Uplandspruce-hardwood,10ll'landspruce-har<h.,rood,alpinetundra,some10""brush-bog/muskeg.Caribouconcentrations,moosepre-sent,Dansheepinhighareas,blackbearinforestedarea.Caribouconcentrationssouthofcanyons,moosepresentinmoreopenpartsofcanyons,Dallsheepinhighareas,blackbearpresent.Moto1tain.Moto1tain.HighwindsreportedbyGVEAtohave}mockeddown138KVtowers.McKinleyweather:annualtemperature27.7F.,annualprecip-itation14.50".DenalialonghSeveralKinleyfRiver.andMcKj(FAAatWellsCreek-DeanCreek(14)26miles.4,000'atWellsPass.WidevalleynarrowingtothenorthtopasswithLouisCreek,ahighsaddle.AbruptdropintoLouisCreek,downtoYanertForkandextremelywideaggradingchannel.Thinsoilsandrock,verysteepslopes.Levelareaspoorlydrained.Lowlandspruce-hardwood,uplandspruce-hardwood,lowbrush-nruskeg/bog,andalpinettmdra.HighbrushinYanertValley.Caribouconcentrations,mooseinlowerelevations,Dallsheepinhighareas,blackbearinforestedarea,?Tizzlybearin.higherareas.Mountain.DeanCreek-Healy(5)HealytoEster(16)Thinrockysoilsandrock,steep24;Ules.27001atMoodyPass.slopesonupperparts.Steep.Northupwidevalleyandoverll'idegravellypoorlydrainedsoilswithflatpassintosinuousv-canyon,:rariaJ:>lep:nnafrosttableincon-droppingintowidervalleyofHealyJto1ctl.onWIthsteepgravelly""ellCreek.~drainedgraysoils,shallo""bed-rock.Moderateerosionpotential.97miles.1400'atHealy.3501atHealy-Ne~:Well-drained.brownNenana,15001inGoldstreamHills.gravel:01.1sandpoorlydramedWide,terracedvalleyofNenanaloamsWI.thsmfacepeat,shall~flowsnorthtomergewithTanana.permafro:ttable.Nenana-~ster.floodplain.OverTananaRiver""ell-drame~brownloamsw1.th.trendingN.E.arelowrollinghillslenses~ffmesandpoorlydramedActivefaultatHealy.Ice-richloamsW1.thsmfacepea~,shallc;wclayandsiltatl>bo.dy.pe~frosttab~e.MediumtohIghLoIl'landspruce-hardwood,uplandspruce-har<h,;,ood,1011'brush-mus-keg/bog(inpassarea),alpinetto1dra(ridgesalonglo""erMoodyCre~k).Bottomlandspruce-poplar,upland·spruce-har<hl'ood,lowlandspruce-hardwood,10'1';'brush-muskeg/bog,levelareastendtobogs,northslopesarelowlandspruce-hard-.",'ood,swmyslopesareuplandspruce-hard""ood.Caribouconcentrations,mooseinlowerelevations,Dallsheepinhighareas,blackbearinforestedareas,grizzlybearinhigherareas.CaribouconcentrationsonwestbankofNenanabetweenHealyandsouthofClearAFB,moosealongwholeroute,blackbearinfor-estedareas.Mountain.Interior.Healyweather:annualtemperature26.4"F.,armualpre~cipitation11.34"NoneinMinesatSmallcottionlimFAAstatiNenana,(DeanCreektoEster(WoodP.iver)(17)110miles.43001atDean-NoodPasstJpperWoodRiver:ThinrockysoilsDeanCreek,sharpmotmtainvalleyLo""erWoodRiver:Poorlydrainedl).eadsinhighpassintoWoodRiver,loamysoils'dthsurfacepeatandau-shapedglaciervalleyll'ithag-shallo""pennafrosttable.Shallowgradingstream.lI'11icheventuallyslopes.SomewelldrainedbrmmdebouchesontoTananafloodplain,nonacidsoils.Loll'tomediumero-.:patandpoorlydrained.sionpotential.AIpinettmdra,highbrush,lowCaribouconcentrationsinupperbrushbogandmuskeg,moisttmdra,WoodRiver,moosepresentinlowerIrO'll'lan~spT1;1ce-hard""oo~,lOI\'erelevationsandstreambottoms,Dalli\oodRiverl.SareaofmterspersedsheeponhighareasofupperWoodbogsandleveesandmotmdsldthRiver,blackandgrizzlybearpre-correspondingvegetat~vepatterns.sent.MOlmtain.mostpartinterior.BlairL ~ANDMATANUSI<ACORRIDORSINVENTORYSCENICQUALITY/RECREATIONDELTA/MATANUSAEXISTINGRIGHTS-OF-WAY22LANDOWNERSHIP/STATUSSTINGDEVELOPMENTSWILDLIFECLIMATEEX!,TangleLakesArcheologicalDis-Stateselections,Nativeregionaltrict(NationalRegister).DenaliCampgrotmd.TangleRiverBoat.None.Lowtonopotentialf?rdeficiencywithdrawals,m;dD-~.Latmch.Highscenicquality-Nelchinacaribouherd(61,000incommercialforestingandagn.-withdrawals.DenaliDamsl!eWlth-DenaliHighway.easilyaccessiblewithgoodviewsllpland1967),moosepresentinmoderatelyI>1otmtain.cultureduetosoils.drawal.heaarotmdDenahDam-tonorthofMt.Hayessectionof.h.boghighmunbers,blackandgrizzlysiteiswithinHt.M:.Kinleyco-AlaskaRange,CleaTh'aterandbears,ll'Olvespresent.op.Managementzone.Amph.itheaterI>btmta~..ProposedHistoricalSites:RapidsBigneitabisonherdfallrangeConsiderablesettlementalongHuntingLodge,Mile220;BigDeltaRichardsonHighway,AlyeskaRoadhouse,Mile252.Clea1'loJater,(200animals),Dallsheepco~n.highwaynearFairbanks.MilitaryStateselections,utilitycorridorPipeline.Donnelly,FieldingLake,WaysidetypesonAlaskaRange,blackandgn.zzly.bases,tOl'illSofBigDeltaandandmilitaryreservations.Parks.DeltaCampgrmmd,proposed)plarbears,goodduckhabitatinsloughsInterior.DeltaJunction,potentialagri-DeltaWildRiver.ExcellentviewsandexbendsofOlenaandSalchacultureatBigDelta-CleaTh'aterofAlaskaRangefromBigDeltaRiversandmorainalpondsofDon-Lake.south.Easilyaccessible.nellyfume.ToeastisLakeLouisecomplexofrecreationalland.HighscenicLowtonopotentialforNativeregionaldeficiencyandquality-landoflakesandponds.i;lowNelchinacaribouherd,mooseinNone.stateselections.WatanaandVeeNone.Accessiblebydirtroadfrommoistmoderatelyhighnumbers,blackI>buntain/interior.commercialforestryoragricul-powersitewithdrawals.GlennHighwaytoLakeLouiseorandgrizzlybears,'h'Olvespresent.~ureduetosoils.byfloatplane.Sourd~~ghLodge(NationalRegister)Nelchinacaribouhere,veryhighProposedhistoricalsitesofI>1c-Creary'sRoadhouse,Mile104;mooseconcentrationsonGulkanaTownsofGlennallen,Gulkana,-GakonaRoadhouse,l>fi.le132;Pax-drainage,blackandgrizzlybears,settlementalonghighway.Recrea-StateselectionsandUtilityRichardsonHighway,AlyeskaPipe-sonLakeWaysidePark;Sourdoughwolvespresent,goodduckhabitattionaldevelopmentnorthofGlennCorridor.Nativevillagewith-Campground,DryCreekWayside,lWbrushalongGulkanafromSUmmitandInterior.Highway.Thisarea~lowdrawalsofGulkana,Gakona,line,GlennHighway.LittleNelchina,TolsonaandLakePaxsonLakes,ThawLakes.GulkanapotentialforcommercJ.alforestryTazlinaandCopperCenter.LouiseWaysides.ProposedPaxsonismostimportantfisheryinCop-andagricultureduetotheIAHPLakeRecreationheaandGulkanaperRiversystem.Paxsonandtypesoilspresent.WildRiver.HightomediumSUJIDllitLakesareimportantfishscenicqUality.lakes.KnikArcheologicalSite--IndependenceMinesnearPalmerStateselectionsprimarily.SomeONationalRegister).BigLake!Considerabledevelopmentinl>hta-NativeregionaldeficiencyandRockyLakeWaysides.Olugach)WbrushMoosepresent,blackandgrizzlynuskaValley.CoaldepositsnearD-llands.Nativevillagewith-GlennHighway,AlaskaRailroad,StateParktosouth.Matanuskalce-bear,DallsheeponsurroundingTransition/mountain.Sutton.Fanninginlowervalley,drawalsofChickaloon,Eklutnavarioussmallroads.Valleyishighscenicquality~-poplarmountains.recreationusealongKnikArm.andKnik.area.Severalscenicoverlooksalonghighway.Highlyvividlandscape.KINVENTORY~ANDMATANUSI<ACORRIDORSINVENTORYSCENICQUALITY/RECREATIONDELTA/MATANUSAEXISTINGRIGHTS-OF-WAY22LANDOWNERSHIP/STATUSSTINGDEVELOPMENTSWILDLIFECLIMATEEX!,TangleLakesArcheologicalDis-Stateselections,Nativeregionaltrict(NationalRegister).DenaliCampgrotmd.TangleRiverBoat.None.Lowtonopotentialf?rdeficiencywithdrawals,m;dD-~.Latmch.Highscenicquality-Nelchinacaribouherd(61,000incommercialforestingandagn.-withdrawals.DenaliDamsl!eWlth-DenaliHighway.easilyaccessiblewithgoodviewsllpland1967),moosepresentinmoderatelyI>1otmtain.cultureduetosoils.drawal.heaarotmdDenahDam-tonorthofMt.Hayessectionof.h.boghighmunbers,blackandgrizzlysiteiswithinHt.M:.Kinleyco-AlaskaRange,CleaTh'aterandbears,ll'Olvespresent.op.Managementzone.Amph.itheaterI>btmta~..ProposedHistoricalSites:RapidsBigneitabisonherdfallrangeConsiderablesettlementalongHuntingLodge,Mile220;BigDeltaRichardsonHighway,AlyeskaRoadhouse,Mile252.Clea1'loJater,(200animals),Dallsheepco~n.highwaynearFairbanks.MilitaryStateselections,utilitycorridorPipeline.Donnelly,FieldingLake,WaysidetypesonAlaskaRange,blackandgn.zzly.bases,tOl'illSofBigDeltaandandmilitaryreservations.Parks.DeltaCampgrmmd,proposed)plarbears,goodduckhabitatinsloughsInterior.DeltaJunction,potentialagri-DeltaWildRiver.ExcellentviewsandexbendsofOlenaandSalchacultureatBigDelta-CleaTh'aterofAlaskaRangefromBigDeltaRiversandmorainalpondsofDon-Lake.south.Easilyaccessible.nellyfume.ToeastisLakeLouisecomplexofrecreationalland.HighscenicLowtonopotentialforNativeregionaldeficiencyandquality-landoflakesandponds.i;lowNelchinacaribouherd,mooseinNone.stateselections.WatanaandVeeNone.Accessiblebydirtroadfrommoistmoderatelyhighnumbers,blackI>buntain/interior.commercialforestryoragricul-powersitewithdrawals.GlennHighwaytoLakeLouiseorandgrizzlybears,'h'Olvespresent.~ureduetosoils.byfloatplane.Sourd~~ghLodge(NationalRegister)Nelchinacaribouhere,veryhighProposedhistoricalsitesofI>1c-Creary'sRoadhouse,Mile104;mooseconcentrationsonGulkanaTownsofGlennallen,Gulkana,-GakonaRoadhouse,l>fi.le132;Pax-drainage,blackandgrizzlybears,settlementalonghighway.Recrea-StateselectionsandUtilityRichardsonHighway,AlyeskaPipe-sonLakeWaysidePark;Sourdoughwolvespresent,goodduckhabitattionaldevelopmentnorthofGlennCorridor.Nativevillagewith-Campground,DryCreekWayside,lWbrushalongGulkanafromSUmmitandInterior.Highway.Thisarea~lowdrawalsofGulkana,Gakona,line,GlennHighway.LittleNelchina,TolsonaandLakePaxsonLakes,ThawLakes.GulkanapotentialforcommercJ.alforestryTazlinaandCopperCenter.LouiseWaysides.ProposedPaxsonismostimportantfisheryinCop-andagricultureduetotheIAHPLakeRecreationheaandGulkanaperRiversystem.Paxsonandtypesoilspresent.WildRiver.HightomediumSUJIDllitLakesareimportantfishscenicqUality.lakes.KnikArcheologicalSite--IndependenceMinesnearPalmerStateselectionsprimarily.SomeONationalRegister).BigLake!Considerabledevelopmentinl>hta-NativeregionaldeficiencyandRockyLakeWaysides.Olugach)WbrushMoosepresent,blackandgrizzlynuskaValley.CoaldepositsnearD-llands.Nativevillagewith-GlennHighway,AlaskaRailroad,StateParktosouth.Matanuskalce-bear,DallsheeponsurroundingTransition/mountain.Sutton.Fanninginlowervalley,drawalsofChickaloon,Eklutnavarioussmallroads.Valleyishighscenicquality~-poplarmountains.recreationusealongKnikArm.andKnik.area.Severalscenicoverlooksalonghighway.Highlyvividlandscape.KINVENTORY TOPOGRAPHY/GEOLOGYSOILSVEGETATIONWILDLIFEDELTAANDMATANUSKACORRIDORSINVENTORYCLIMATEE'98miles.4000'nearRockCreek.lowareas:poorlydrainedsoilsVariesfromwide,flat,openter-withsurfacepeatandshallowraintorolling,post-glacialpermafrosttable.Textures.terrain.Valleyfloorsarerangefromgravellytofine.Nelchinacaribouherd(61,000inNone•WatanatoPaxsonviausuallywideandflat,poorlySlopes:Well-drained,thm,Lowlandspruce-hardwood;upland1967),moosepresentmmoderatelyCOTrnnelB.utb~:Creek(18)drained.l>tanylakes,kettles,stronglyacidsoilsjdeepspruce-hardwood,lowbrushboghighnl.DTlbers,blackandgrizzly.l>buntain.cultUlandmorainalridgeseasttoMac-permafrosttable.Mediumtoandmuskegmoisttundra.bears,l'lOlvespresent.larenRiver.Thisuplandareahigherosionpotential.Large-containsaltiplanationterracesareasareentiresoilsof101'1-andisunderlainwithdiscon-lyingtypewhichisveryvul-t~uouspermafrost.nerabletofrosth~a~g.Lowareas:Poorlydrainedsoilswithsurfacepeatandshallow,BigDeitabisonherdfallrange152miles.2700'atPaxson,3000'permafrosttable.Slopes:WellConside:atIsabelPass.Rollinghillsatdrainedsoils;somethaw;some(200animals),DallsheepcommonhighwayPaxsonleadtohighflatpassandcontaininglensesoffives.FullrangeofvegetativetypesonAlaskaRange,blackandgrizzly,bases,PaxsontoFairbanksnorthtoU-shape1'-buntainValleyShallowtodeeppermafrosttable,frombottomlandspruce-poplarbears,goodduckhabitatinsloughsInterior.Delta31nearRainbowRidge-BlackRapidsifany.Mediumerosionpoten-toalpinetundra.andexbendsofO1enaandSalchaculture(19)area.RollinghillsnearDon-tial.RockysoilandbedrockinRiversandmorainalpondsofDonMLake.nellyDomedecreasetoflatlandDeltaCanyonarea.ThixotropicnellyDome.byEielsonAPE.siltsjustnorthofSummitLake.PennafrostcontinuousfromShawCreektoTananaRiver.LOwareas:Poorlydrainedsoilswithpeatysurface;shallowper-90miles.3000'elevationatplatMmafrosttable.MediumerosioneauatheadofLittleNelchinapotential.Uplands:WellUplandspruce-hardwood;lowNelchinacaribouherd,mooseinNone.WatanatoSlideMtn.River.GeneraJIyflatandrollingdrainedthinsoilswithdarkbrushbogandmuskeg;moistmoderatelyhighnl.DTlbers,black1'-buntain/interior.commercviaVee(20).,terrain;ahighplateauextendingacidsurface;deeppermafrdsttmdra.andgrizzlybears,'""'DIvespresent.':uredlfromSusitnaRivertoLakeLouisetable.Gravellytexture.Med-area.!I.\nnerouslakesandbogs.iumerosionpotential.Perma-frostiscontinuousonthispoorlydrained,ice-richareaoffinesediments.Maj?rportionofroute:PoorlyNelchinacaribouhere,veryhighmooseconcentrationsonGulkanaTownsojdramed,finegrainsoilswithdrainage,blackandgrizzlybears,119miles.2700'atPaxson.surfacepeat;shallowpermafrostweIvespresent,goodduckhabitatsettlerrnPaxsontoSlideMtn.Rollinghillsandflatplateaus,table.MediLmlerosionpotential.Lowlandspruce-hardwood,lowbrushalongGulkanafromSummitandtional(viaG~ennallen(21)cutbyincisedstreams.PoorlyUplandareas:Welldrainedbogandmuskeg.PaxsonLakes,ThawLakes.GulkanaInterior.Highway.drained,havingmanylakesand,thin,stronglyacidsoilswithismostimportantfisheryinCop-potenti.bogs.deeppermafrosttable.Perma-perRiversystem.Paxsonandandagr:frostiscontinuousinthisStnrndtLakesareimportantfishtypeso:area.lakes.~ID8miles.3000'atTahnetaPass.Widepassapproachedfromeastbe-MatanuskaValley:Welldrainedcomesnarrowvalleytowestofpass.Incisedriverandlow.loamyorgravellygraysoilsandLowlandspruce-hardwood,lowbrushMoosepresent,blackandgrizzlyConsideIridgesoccupyvalleyboundedbystronglyacidsoils.MediumtonuskaVaSlideMts,toPoint'higherosionpotential.Knikbogandmuskegjuplandspruce-bear,DallsheeponsurroundingTransition/mountain.majormountainrangesonnorthhar~wood;Bottomlandspruce-poplarSutton.MacKenzie(22)ap.dsouth.Valleydeboucheson-Ann:PoorlydrainedfibrouslTlOtmtains.recreatitol>htanuska-Knikfloodplain,peat,VUlnerabletofrostheaving,.agnculturalland.'toPt.McKenzie,routecrossesandwelldrainedacidsoils.1.0'1'manylakesonflatfloodplainstomediumerosionpotential.~dpoorlydraineduplands.TOPOGRAPHY/GEOLOGYSOILSVEGETATIONWILDLIFEDELTAANDMATANUSKACORRIDORSINVENTORYCLIMATEE'98miles.4000'nearRockCreek.lowareas:poorlydrainedsoilsVariesfromwide,flat,openter-withsurfacepeatandshallowraintorolling,post-glacialpermafrosttable.Textures.terrain.Valleyfloorsarerangefromgravellytofine.Nelchinacaribouherd(61,000inNone•WatanatoPaxsonviausuallywideandflat,poorlySlopes:Well-drained,thm,Lowlandspruce-hardwood;upland1967),moosepresentmmoderatelyCOTrnnelB.utb~:Creek(18)drained.l>tanylakes,kettles,stronglyacidsoilsjdeepspruce-hardwood,lowbrushboghighnl.DTlbers,blackandgrizzly.l>buntain.cultUlandmorainalridgeseasttoMac-permafrosttable.Mediumtoandmuskegmoisttundra.bears,l'lOlvespresent.larenRiver.Thisuplandareahigherosionpotential.Large-containsaltiplanationterracesareasareentiresoilsof101'1-andisunderlainwithdiscon-lyingtypewhichisveryvul-t~uouspermafrost.nerabletofrosth~a~g.Lowareas:Poorlydrainedsoilswithsurfacepeatandshallow,BigDeitabisonherdfallrange152miles.2700'atPaxson,3000'permafrosttable.Slopes:WellConside:atIsabelPass.Rollinghillsatdrainedsoils;somethaw;some(200animals),DallsheepcommonhighwayPaxsonleadtohighflatpassandcontaininglensesoffives.FullrangeofvegetativetypesonAlaskaRange,blackandgrizzly,bases,PaxsontoFairbanksnorthtoU-shape1'-buntainValleyShallowtodeeppermafrosttable,frombottomlandspruce-poplarbears,goodduckhabitatinsloughsInterior.Delta31nearRainbowRidge-BlackRapidsifany.Mediumerosionpoten-toalpinetundra.andexbendsofO1enaandSalchaculture(19)area.RollinghillsnearDon-tial.RockysoilandbedrockinRiversandmorainalpondsofDonMLake.nellyDomedecreasetoflatlandDeltaCanyonarea.ThixotropicnellyDome.byEielsonAPE.siltsjustnorthofSummitLake.PennafrostcontinuousfromShawCreektoTananaRiver.LOwareas:Poorlydrainedsoilswithpeatysurface;shallowper-90miles.3000'elevationatplatMmafrosttable.MediumerosioneauatheadofLittleNelchinapotential.Uplands:WellUplandspruce-hardwood;lowNelchinacaribouherd,mooseinNone.WatanatoSlideMtn.River.GeneraJIyflatandrollingdrainedthinsoilswithdarkbrushbogandmuskeg;moistmoderatelyhighnl.DTlbers,black1'-buntain/interior.commercviaVee(20).,terrain;ahighplateauextendingacidsurface;deeppermafrdsttmdra.andgrizzlybears,'""'DIvespresent.':uredlfromSusitnaRivertoLakeLouisetable.Gravellytexture.Med-area.!I.\nnerouslakesandbogs.iumerosionpotential.Perma-frostiscontinuousonthispoorlydrained,ice-richareaoffinesediments.Maj?rportionofroute:PoorlyNelchinacaribouhere,veryhighmooseconcentrationsonGulkanaTownsojdramed,finegrainsoilswithdrainage,blackandgrizzlybears,119miles.2700'atPaxson.surfacepeat;shallowpermafrostweIvespresent,goodduckhabitatsettlerrnPaxsontoSlideMtn.Rollinghillsandflatplateaus,table.MediLmlerosionpotential.Lowlandspruce-hardwood,lowbrushalongGulkanafromSummitandtional(viaG~ennallen(21)cutbyincisedstreams.PoorlyUplandareas:Welldrainedbogandmuskeg.PaxsonLakes,ThawLakes.GulkanaInterior.Highway.drained,havingmanylakesand,thin,stronglyacidsoilswithismostimportantfisheryinCop-potenti.bogs.deeppermafrosttable.Perma-perRiversystem.Paxsonandandagr:frostiscontinuousinthisStnrndtLakesareimportantfishtypeso:area.lakes.~ID8miles.3000'atTahnetaPass.Widepassapproachedfromeastbe-MatanuskaValley:Welldrainedcomesnarrowvalleytowestofpass.Incisedriverandlow.loamyorgravellygraysoilsandLowlandspruce-hardwood,lowbrushMoosepresent,blackandgrizzlyConsideIridgesoccupyvalleyboundedbystronglyacidsoils.MediumtonuskaVaSlideMts,toPoint'higherosionpotential.Knikbogandmuskegjuplandspruce-bear,DallsheeponsurroundingTransition/mountain.majormountainrangesonnorthhar~wood;Bottomlandspruce-poplarSutton.MacKenzie(22)ap.dsouth.Valleydeboucheson-Ann:PoorlydrainedfibrouslTlOtmtains.recreatitol>htanuska-Knikfloodplain,peat,VUlnerabletofrostheaving,.agnculturalland.'toPt.McKenzie,routecrossesandwelldrainedacidsoils.1.0'1'manylakesonflatfloodplainstomediumerosionpotential.~dpoorlydraineduplands. ENVIRONMENTALASSESSMENTOFCORRIDORSTheproposedcorridorisacombinationofthecorridorsSusitna-landNenana-I.Thecommonfeatureofbothistheirparallelingoftheexist-ingAlaskaRailroadcorridor.TheNenana-lcorridoristheshortestandmosteconomicalcorridorconnectingDevilCanyontoEster,andis198mileslong.The136-milelongSusitna-lcorridorisonlytwomileslongerthantheshortestcorridorconnectingDevilCanyontoPointMacKenziebutsinceitadheresmorecloselytotheexistingcorridors.isthemosteconomicaland,atthesametime,leastenvironmentallydetrimentalcorridor.Susitna-lFromPointMacKenzietheSusitna-lcorridortravelsnorthalongtheeastflankoftheSusitnaValley,arextremelywideandpoorlydrainedplain.Heavyforestsofbottomlandspruceandpoplar.interspersedwithmuskegandblackspruce,aretypical.Thesoilstendtobedeep,verypoorlydrainedpeatsinconjunctionwithwell-drainedgravelsandloams.Thewell-drainedsoilsoccupymorethanhalfofthelowerSusitnaValley,totheeastal,~ngtheterraceflankingthefloodplain,theratioofwelltopoorlyell-ainedsoilsishigher.AlthoughpermafrostisalmostabsentinthislowerpartoftheSusitnaValley,thepoorlydrainedareasaresubjecttofreezingandheavinginwinter.bsizeableconcentrationofmooseinhabitthelowerSusitnaRiver',l]]ey,andthevalleyalsosupportsamoderatedensityofwaterfowl.Buthbrownandblackbeararepresent.AstheSusitna-lcorridorapproachestheNancyLakearea,itmeetsandcrossestheAlaskaRailroadandtheAnchorage-FairbanksHighway,bothofwhichrunnorthwesttosoutheast.Continuingnorthandtotheeastofthehighway/railroadcorridor,theSusitna-lcorridorcrossesseveralmajortributariesoftheSusitnaRiverwhichoriginateintheTalkeetnaMountains.TheseareWillowCreek,SheepCreek.andmoreimportantly,theKashwitnaRiver.Inthisareatheterrainhasbecomemorerolling,andtherelativeproportionofwelldrainedsoilssupportingthickpoplar-spruceforestisconsiderablygreaterthantothesouth.ThetownofTalkeetnaisthefirstsizeablecommunitytobeapproachedbythecorridor.Talkeetnaisasmalltown.originallyastopontheAlaskaRailroad.Recreationplaysastrongroleinthetown'seconomysinceseveralcharterflyingservicesprovideaccesstotheAlaskaRangeandtheTalkeetnaMountains.23ENVIRONMENTALASSESSMENTOFCORRIDORSTheproposedcorridorisacombinationofthecorridorsSusitna-landNenana-I.Thecommonfeatureofbothistheirparallelingoftheexist-ingAlaskaRailroadcorridor.TheNenana-lcorridoristheshortestandmosteconomicalcorridorconnectingDevilCanyontoEster,andis198mileslong.The136-milelongSusitna-lcorridorisonlytwomileslongerthantheshortestcorridorconnectingDevilCanyontoPointMacKenziebutsinceitadheresmorecloselytotheexistingcorridors.isthemosteconomicaland,atthesametime,leastenvironmentallydetrimentalcorridor.Susitna-lFromPointMacKenzietheSusitna-lcorridortravelsnorthalongtheeastflankoftheSusitnaValley,arextremelywideandpoorlydrainedplain.Heavyforestsofbottomlandspruceandpoplar.interspersedwithmuskegandblackspruce,aretypical.Thesoilstendtobedeep,verypoorlydrainedpeatsinconjunctionwithwell-drainedgravelsandloams.Thewell-drainedsoilsoccupymorethanhalfofthelowerSusitnaValley,totheeastal,~ngtheterraceflankingthefloodplain,theratioofwelltopoorlyell-ainedsoilsishigher.AlthoughpermafrostisalmostabsentinthislowerpartoftheSusitnaValley,thepoorlydrainedareasaresubjecttofreezingandheavinginwinter.bsizeableconcentrationofmooseinhabitthelowerSusitnaRiver',l]]ey,andthevalleyalsosupportsamoderatedensityofwaterfowl.Buthbrownandblackbeararepresent.AstheSusitna-lcorridorapproachestheNancyLakearea,itmeetsandcrossestheAlaskaRailroadandtheAnchorage-FairbanksHighway,bothofwhichrunnorthwesttosoutheast.Continuingnorthandtotheeastofthehighway/railroadcorridor,theSusitna-lcorridorcrossesseveralmajortributariesoftheSusitnaRiverwhichoriginateintheTalkeetnaMountains.TheseareWillowCreek,SheepCreek.andmoreimportantly,theKashwitnaRiver.Inthisareatheterrainhasbecomemorerolling,andtherelativeproportionofwelldrainedsoilssupportingthickpoplar-spruceforestisconsiderablygreaterthantothesouth.ThetownofTalkeetnaisthefirstsizeablecommunitytobeapproachedbythecorridor.Talkeetnaisasmalltown.originallyastopontheAlaskaRailroad.Recreationplaysastrongroleinthetown'seconomysinceseveralcharterflyingservicesprovideaccesstotheAlaskaRangeandtheTalkeetnaMountains.23 TalkeetnaisattheconfluenceoftheSusitna,Chulitna,andTalkeetnaRivers;thecorridorcrossesonlytheTalkeetnaRiveratthispoint.Therollingterrainencounteredtothesouthismorepronouncedhere,andthevalleyoftheSusitnaRivernarrowsconsiderablyaboveTalkeetna.Thehighwayturnswestabout15milessouthofTalkeetna;therailroadcontinuesnorthovertheTalkeetnaRiverandfollowstherivernorthtoGoldCreek.ThewestbankoftheriveristheeasternboundaryofDenaliStatePark.AtGoldCreektheSusitnaRiverflowsdownfromtheeast;therailroadcontinuesnorthtoChulitnaandaneventualre-convergencewiththehighway.TheSusitna-lcorridorfollowstheriveralongtheincreas-inglyrestrictedvalleytotheDevilCanyonpowersite.Alongthevalleyfloorandwallsareforestsofspruceandhardwoodsbasedonrelativelywelldrainedsoils.Theuplandsabovethevalleysupportsparserforests,andincreasingamountsofpermafrostsoilsareencountered.TheSusitna-lcorridortraversesn,oseconcentrationsforitsentirelength;waterfowldensitydropsfrommoderatetolownorthoftheTalkeetnaRiver.TheNenana-lcorridorret:cacespartoftheSusitna-lcorridortoGoldCreek,butleadsnorthtoChl.:iitna,parallelingtherailroad,andeventu-allythehighway,also.PastChulitnathecorridorlieswithinthewatershedoftheChulitnaRiveruntilBroadPassiscrossed.TheChulitnaValleyisrelativelywide,witharollingfloor,andincised1'1.rsandstreams.Thevalleyleadsuptothenortheast,andthe• vrollinghillsonthefloorandflanksreflectthisorientation.Thesoilsherearepoorlydrainedclaysalongtheriverbottoms,andwelldrainedbutthinsoils.Permafrost,whenpresent,isrelativelydeep.Theforestsherearesparseandbecomemoresoastheheadofthepassisapproached;generallyuplandspruce-hardwood,theyareinterspersedwithbogsandmuskegsinpoorlydrainedareas.Somemooseconcentrationsaretraversed;Dallsheepinhabitthesurround-inguplandareas.TothenorthofBroadPasstheNenana-lcorridorlieswithintheNenanawatershed,droppingfromamaximumelevationof2,400feetatSummit.BroadPass,drainedbyatributaryoftheNenana,alsomaintainsthegeneralcharacterofthepassuntilCantwell,atwhichpointtheNenana-l24TalkeetnaisattheconfluenceoftheSusitna,Chulitna,andTalkeetnaRivers;thecorridorcrossesonlytheTalkeetnaRiveratthispoint.Therollingterrainencounteredtothesouthismorepronouncedhere,andthevalleyoftheSusitnaRivernarrowsconsiderablyaboveTalkeetna.Thehighwayturnswestabout15milessouthofTalkeetna;therailroadcontinuesnorthovertheTalkeetnaRiverandfollowstherivernorthtoGoldCreek.ThewestbankoftheriveristheeasternboundaryofDenaliStatePark.AtGoldCreektheSusitnaRiverflowsdownfromtheeast;therailroadcontinuesnorthtoChulitnaandaneventualre-convergencewiththehighway.TheSusitna-lcorridorfollowstheriveralongtheincreas-inglyrestrictedvalleytotheDevilCanyonpowersite.Alongthevalleyfloorandwallsareforestsofspruceandhardwoodsbasedonrelativelywelldrainedsoils.Theuplandsabovethevalleysupportsparserforests,andincreasingamountsofpermafrostsoilsareencountered.TheSusitna-lcorridortraversesn,oseconcentrationsforitsentirelength;waterfowldensitydropsfrommoderatetolownorthoftheTalkeetnaRiver.TheNenana-lcorridorret:cacespartoftheSusitna-lcorridortoGoldCreek,butleadsnorthtoChl.:iitna,parallelingtherailroad,andeventu-allythehighway,also.PastChulitnathecorridorlieswithinthewatershedoftheChulitnaRiveruntilBroadPassiscrossed.TheChulitnaValleyisrelativelywide,witharollingfloor,andincised1'1.rsandstreams.Thevalleyleadsuptothenortheast,andthe•vrollinghillsonthefloorandflanksreflectthisorientation.Thesoilsherearepoorlydrainedclaysalongtheriverbottoms,andwelldrainedbutthinsoils.Permafrost,whenpresent,isrelativelydeep.Theforestsherearesparseandbecomemoresoastheheadofthepassisapproached;generallyuplandspruce-hardwood,theyareinterspersedwithbogsandmuskegsinpoorlydrainedareas.Somemooseconcentrationsaretraversed;Dallsheepinhabitthesurround-inguplandareas.TothenorthofBroadPasstheNenana-lcorridorlieswithintheNenanawatershed,droppingfromamaximumelevationof2,400feetatSummit.BroadPass,drainedbyatributaryoftheNenana,alsomaintainsthegeneralcharacterofthepassuntilCantwell,atwhichpointtheNenana-l24 corridorconvergestotheNenanaRiver.Acrossingisnecessary,asthewestbankoftheNenananorthofCantwellistheboundaryoftheMountMcKinleyNationalPark.FollowingtheeastbankoftheNenanathecorridorpiercestheAlaskaRange,emergingatHealy.ThevalleyoftheNenanabecomesconstrictedinitspassagethroughtheAlaskaRange;intwostretchesitisparticularlyrestricted.TheentranceoftheNenanaRiverimmediatelynorthofCantwellisatightvalleyhemmedinbyloose,shaleytalusconesfor10or15miles.Downstream,awidevalleyattheconfluenceofYanertForkseparatesthisuppercanyonfromacanyonfurtherdownriverbytheMcKinleyParkHeadquarters.Thislowercanyonisevenmorerestrictedthantheuppercanyon;thehighwayisforceddownnexttotheriver,andbluffsandunstableslopesflankbothsides.Thevegetationinthecanyonsvariesfromuplandspruce-hardwoodtoalpinetundra;soilsvaryfrompoodydrainedriverbottomstounstabletalus.SomelocalizedmooseCCiBCC'1trationsarecrossed,particularlyintheYanertForkconfluence;intherestrictedcanyonsDallsheephabitatisencountered.HeadingnorthwardoutoftheAlaskaRange,theNenana-lcorridordebouchesontotheplainsarcundHealy.TheNenanaRiverisstronglyincisedfromHealynorthwardforabout20miles,andterracesareprom-inentalongbothbanks.Thesoilsvaryfrompoorlydrainedsoilsontheterraceflatsandriverbottomtowelldrainedsoilsontheslopes.Theseeditionsarereflectedinthevegetation,whichtendstobeblackspruce"odmuskegonthebottomlandsandflats,andspruce-hardwoodsonthet:>1opes.CoalisexposedonslopesontheeastbanksoftheNenanaRiver.TheUsibelliMiningCompanyatHealyprovidesfuelfortheGoldenValleyElectricAssociationsteamplant,whichisthesouthernterminusofa138-kvtransmissionlinetoEster.TheNenana-lcorridorparallelstheAlaskaRailroadandAnchorage-FairbanksHighway.ScenicqualitynorthofHealyismoderatetolow;theterrainisflat,blanketedwithafairlyuniformmosaicofspruce-hardwoodsandmuskeg.AstheTananaRiverisapproached,thelandbecomesflatterandtheforestdensityheavier;theNenanadividesintomanybranchesandsloughsnearitsmouth.TheentirestretchofcorridorfromHealytoNenanatraversesgoodmoosehabitat;overthewestbankoftheNenanaRiverliesaconsiderable25corridorconvergestotheNenanaRiver.Acrossingisnecessary,asthewestbankoftheNenananorthofCantwellistheboundaryoftheMountMcKinleyNationalPark.FollowingtheeastbankoftheNenanathecorridorpiercestheAlaskaRange,emergingatHealy.ThevalleyoftheNenanabecomesconstrictedinitspassagethroughtheAlaskaRange;intwostretchesitisparticularlyrestricted.TheentranceoftheNenanaRiverimmediatelynorthofCantwellisatightvalleyhemmedinbyloose,shaleytalusconesfor10or15miles.Downstream,awidevalleyattheconfluenceofYanertForkseparatesthisuppercanyonfromacanyonfurtherdownriverbytheMcKinleyParkHeadquarters.Thislowercanyonisevenmorerestrictedthantheuppercanyon;thehighwayisforceddownnexttotheriver,andbluffsandunstableslopesflankbothsides.Thevegetationinthecanyonsvariesfromuplandspruce-hardwoodtoalpinetundra;soilsvaryfrompoodydrainedriverbottomstounstabletalus.SomelocalizedmooseCCiBCC'1trationsarecrossed,particularlyintheYanertForkconfluence;intherestrictedcanyonsDallsheephabitatisencountered.HeadingnorthwardoutoftheAlaskaRange,theNenana-lcorridordebouchesontotheplainsarcundHealy.TheNenanaRiverisstronglyincisedfromHealynorthwardforabout20miles,andterracesareprom-inentalongbothbanks.Thesoilsvaryfrompoorlydrainedsoilsontheterraceflatsandriverbottomtowelldrainedsoilsontheslopes.Theseeditionsarereflectedinthevegetation,whichtendstobeblackspruce"odmuskegonthebottomlandsandflats,andspruce-hardwoodsonthet:>1opes.CoalisexposedonslopesontheeastbanksoftheNenanaRiver.TheUsibelliMiningCompanyatHealyprovidesfuelfortheGoldenValleyElectricAssociationsteamplant,whichisthesouthernterminusofa138-kvtransmissionlinetoEster.TheNenana-lcorridorparallelstheAlaskaRailroadandAnchorage-FairbanksHighway.ScenicqualitynorthofHealyismoderatetolow;theterrainisflat,blanketedwithafairlyuniformmosaicofspruce-hardwoodsandmuskeg.AstheTananaRiverisapproached,thelandbecomesflatterandtheforestdensityheavier;theNenanadividesintomanybranchesandsloughsnearitsmouth.TheentirestretchofcorridorfromHealytoNenanatraversesgoodmoosehabitat;overthewestbankoftheNenanaRiverliesaconsiderable25 caribouwinterrange.Despitethelargenumbersofmuskegandponds,particularlytowardNenana,thisstretchisalow-densitywaterfowlhabitat.ThecorridorcrossestheTananaRiver,amajortributaryoftheYukonRiver,andascendsthehillsimmediatelytothenorth.Thesehillsvarybetween1,400and1,800feetinelevation,andareorientedinalongridgeflankingthenorthbankoftheTananaRiver.Thefinegrainsoiliseasilyerodedandisunderlainbypermafrostatvaryingdepths.Thesoiliswelldrainedonslopesandpoorlydrainedoncreekbottoms,andsupportsamoderatelydenseforestofuplandandlowlandspruce-hard-wood.Smallconcentrationsofmoosehabitatarecrossedbythecorridor.Noothermajorwildlifehabitatsexistinthisstretch.Historically,goldminingwasextensivehere,usuallyintheformofdredging.Thecreekbottomsareoftenpatternedwithdepositedtail-ingsfrompreviousworkages.TheendpointofEsterreflectspreviousd"edgingactivity;considerablesp,Isoccupymoststreambottoms.EsterisanoutlyingcommunityofFairbanks,andthelocationoftheGoldHillsubstation,theassumedterminusoftheNenana-lcorridor.AlternativeSusitna-2AlternativecorridorSusitna-2is140mileslong,4mileslongerthanSusitna-l,ItdiffersfromSusitna-linthatfromTalkeetnaitcrossestheSusitnaRiver,headsnorthintoDenaliStatePark,thennorthwestOVe;TroublesomeCreekandontoGoldCreekwhereitrejoinsSusitna-l,-isalternatesegmentis42mileslong.Initssouthernparttheenviron-mentalsettingissimilartotheGoldCreek-TalkeetnasegmentofSusitna-2;however,itcrossessomelow,rollingmountains,reachingacrestof2,000feetelevationbeforedroppingbacktotheSusitnaValley.AlpineandmoisttundraecosystemswillbecrossedinadditiontothoseecosystemscrossedonSusitna-l;however,thesearelimitedinextent.AlternativeSusitna-3AlternativecorridorSusitna-3is134mileslong,2milesshorterthanSusitna-l,ItisbasicallyamoredirectcorridorfromTalkeetnatoDevilCanyon,bypassingtheAlaskaRailroadbetweenTalkeetnaandGoldCreek.Thelengthofthealternatesegmentis50miles;thelengthofthecorrespondingsegmentinSusitna-lis52miles.HeadinguptheTalkeetnaRiveritcrossesandheadsnorthupandoveraplateauof26caribouwinterrange.Despitethelargenumbersofmuskegandponds,particularlytowardNenana,thisstretchisalow-densitywaterfowlhabitat.ThecorridorcrossestheTananaRiver,amajortributaryoftheYukonRiver,andascendsthehillsimmediatelytothenorth.Thesehillsvarybetween1,400and1,800feetinelevation,andareorientedinalongridgeflankingthenorthbankoftheTananaRiver.Thefinegrainsoiliseasilyerodedandisunderlainbypermafrostatvaryingdepths.Thesoiliswelldrainedonslopesandpoorlydrainedoncreekbottoms,andsupportsamoderatelydenseforestofuplandandlowlandspruce-hard-wood.Smallconcentrationsofmoosehabitatarecrossedbythecorridor.Noothermajorwildlifehabitatsexistinthisstretch.Historically,goldminingwasextensivehere,usuallyintheformofdredging.Thecreekbottomsareoftenpatternedwithdepositedtail-ingsfrompreviousworkages.TheendpointofEsterreflectspreviousd"edgingactivity;considerablesp,Isoccupymoststreambottoms.EsterisanoutlyingcommunityofFairbanks,andthelocationoftheGoldHillsubstation,theassumedterminusoftheNenana-lcorridor.AlternativeSusitna-2AlternativecorridorSusitna-2is140mileslong,4mileslongerthanSusitna-l,ItdiffersfromSusitna-linthatfromTalkeetnaitcrossestheSusitnaRiver,headsnorthintoDenaliStatePark,thennorthwestOVe;TroublesomeCreekandontoGoldCreekwhereitrejoinsSusitna-l,-isalternatesegmentis42mileslong.Initssouthernparttheenviron-mentalsettingissimilartotheGoldCreek-TalkeetnasegmentofSusitna-2;however,itcrossessomelow,rollingmountains,reachingacrestof2,000feetelevationbeforedroppingbacktotheSusitnaValley.AlpineandmoisttundraecosystemswillbecrossedinadditiontothoseecosystemscrossedonSusitna-l;however,thesearelimitedinextent.AlternativeSusitna-3AlternativecorridorSusitna-3is134mileslong,2milesshorterthanSusitna-l,ItisbasicallyamoredirectcorridorfromTalkeetnatoDevilCanyon,bypassingtheAlaskaRailroadbetweenTalkeetnaandGoldCreek.Thelengthofthealternatesegmentis50miles;thelengthofthecorrespondingsegmentinSusitna-lis52miles.HeadinguptheTalkeetnaRiveritcrossesandheadsnorthupandoveraplateauof26 almost4,000feetelevation.Intheprocess,itcrossesabout30milesofmoisttundrainadditionato20milesofuplandspruce-hardwood.AlternativeSusitna-4AlternativecorridorSusitna-4is149mileslong,13mileslongerthanSusitna-I.AswiththeotheralternativeSusitnacorridors,itdeviatesfromTalkeetna,headinguptheTalkeetnaRiverandPrairieCreektoStephenLake,thenheadingwesttoDevilCanyondamsite.Thissegmentis65milesversusadistanceof52forthecomparablesegmentofSusitna-I.ThiscorridorwillrequireatleastonecrossingoftheTalkeetnaRiver;ittraversestheuplandspruce-hardwoodecosystemformostofitslength,andafewmilesofmoisttundra.Themajorsoilforthissegmentisawelldrainedgravel.Permafrostcanbeexpectedinthehigherelevations.ThecrestofthissegmentisatStephenLake,anelevationof2,200feet.AlternativeNenana-2AlternativecorridorNenana-2is220mileslong,22mileslongerthanNenana-I.ThisalternativedepartsNenana-1atCantwell,headseasttoWellsCreek,northtoDeanCreekandtheWoodRiver,andfollowstheWoodRivernorthtoEster.Thissegmentis158miles.FromCantwellthecorridorparallelsth'CDenaliHighway,thencrossestheNenanaRiverinthevicinityoftheconfluenceofWellsCreek.WellsCreekvalleypro-gressivelynarrowsandsteepensasitsheadisapproached,culminatinga3,900footpassintoLouisCreekwhichdrainsintoYanertFort.FromYanertForkthecorridorleadsupandovertheDeanCreek-WoodRiveruassat4,000feetandfollowstheWoodRiverValleyouttotheTananaRiver\alley.Awidevarietyofecosystemsistraversed,fromalpinetundratobogandmuskeg.Permafrostcanbeassumedtobeprevalent;soilsvaryfrompoorlydrainedpeatstorock.For25to30milesthecorridorrunsadjacenttoorthroughtheBlairLakeAirForceRange.Habitatofmoose,caribouandDallsheeparetraversed.AlternativeNenana-3AlternativecorridorNenana-3is231mileslong,33mileslongerthanNenana-I.ItisidenticaltoNenana-1uptoCantwell;fromCantwellitloopseastandnorththroughtheAlaskaRange,rejoiningNenana-latHealy.Thissegmentis72miles.ThecomparablesegmentofNenana-1is39miles.FromCantwellthecorridorheadseastalongtheNenanaRiverandDenaliHighway,thencenorth,uptheWellsCreekvalley,overthepass(3,900feet)27almost4,000feetelevation.Intheprocess,itcrossesabout30milesofmoisttundrainadditionato20milesofuplandspruce-hardwood.AlternativeSusitna-4AlternativecorridorSusitna-4is149mileslong,13mileslongerthanSusitna-I.AswiththeotheralternativeSusitnacorridors,itdeviatesfromTalkeetna,headinguptheTalkeetnaRiverandPrairieCreektoStephenLake,thenheadingwesttoDevilCanyondamsite.Thissegmentis65milesversusadistanceof52forthecomparablesegmentofSusitna-I.ThiscorridorwillrequireatleastonecrossingoftheTalkeetnaRiver;ittraversestheuplandspruce-hardwoodecosystemformostofitslength,andafewmilesofmoisttundra.Themajorsoilforthissegmentisawelldrainedgravel.Permafrostcanbeexpectedinthehigherelevations.ThecrestofthissegmentisatStephenLake,anelevationof2,200feet.AlternativeNenana-2AlternativecorridorNenana-2is220mileslong,22mileslongerthanNenana-I.ThisalternativedepartsNenana-1atCantwell,headseasttoWellsCreek,northtoDeanCreekandtheWoodRiver,andfollowstheWoodRivernorthtoEster.Thissegmentis158miles.FromCantwellthecorridorparallelsth'CDenaliHighway,thencrossestheNenanaRiverinthevicinityoftheconfluenceofWellsCreek.WellsCreekvalleypro-gressivelynarrowsandsteepensasitsheadisapproached,culminatinga3,900footpassintoLouisCreekwhichdrainsintoYanertFort.FromYanertForkthecorridorleadsupandovertheDeanCreek-WoodRiveruassat4,000feetandfollowstheWoodRiverValleyouttotheTananaRiver\alley.Awidevarietyofecosystemsistraversed,fromalpinetundratobogandmuskeg.Permafrostcanbeassumedtobeprevalent;soilsvaryfrompoorlydrainedpeatstorock.For25to30milesthecorridorrunsadjacenttoorthroughtheBlairLakeAirForceRange.Habitatofmoose,caribouandDallsheeparetraversed.AlternativeNenana-3AlternativecorridorNenana-3is231mileslong,33mileslongerthanNenana-I.ItisidenticaltoNenana-1uptoCantwell;fromCantwellitloopseastandnorththroughtheAlaskaRange,rejoiningNenana-latHealy.Thissegmentis72miles.ThecomparablesegmentofNenana-1is39miles.FromCantwellthecorridorheadseastalongtheNenanaRiverandDenaliHighway,thencenorth,uptheWellsCreekvalley,overthepass(3,900feet)27 toLouisCreekandYanertFork.FromYanertForkthecorridorgoesoveranotherpass(2,900feet)toMoodyCreekandfollowsthiscreektoHealyandNenana-I.Theterrainvariesfromrollinghillsandvalleystohighpassesandsharpridges.Soilsvaryfrompoorlydrainedbottomlandtoexposedbedrock;permafrostisprevalent.Ecosystemscrossedaremoisttundra,alpinetundra,uplandspruce-hardwood,andmuskegandbog.Habitatsofmoose,caribou,andDallsheeparetraversed.Exceptfor22milesparallelingtheDenaliHighway,nootherrights-of-wayareparalleled.AlternativeNenana-4AlternativecorridorNenana-4is223mileslong,25mileslongerthanNenana-I.FromDevilCanyonitleadseastandnorth,eventuallytyingintoNenana-latHealy.Thelengthofthissegmentis126miles;'helengthofthecomparablesegn'ntofNenana-lis101miles.ThecorridorleavesDevilCanyon,headingeasttoWatanaDamsite,andthennorthupDeadmanCreekandBrushkanaCreektoWellsCreek.FromWellsCreekitheadsl:poverthepass(3,900feet)toLouisCreekandYanertFork,overanotherpass(2,900feet)toMoodyCreek,whichitfollowstoHealy.'Theterrainvariesfromrollinghillsandvalleystohighpassesandsharpridges.Soilsvaryfrompoorlydrainedbottomlandtoexposedbedrock;permafrostcanbeassumedtobeprevalent.Ecosystemstraversedaremoisttundra,alpinetundra,muskegandbug,anduplandspruce-hardwood.Habitatsofmoose,caribou,and')a11sheetarecrossed.Thereisnoparallelingofexistingcorridors.AlternativeNenana-5AlternativecorridorNenana-5is212mileslong,14mileslongerthanNenana-I.ItistotallyseparatefromNenana-I,beingaparallelcorridortotheeastofthepreferredcorridor.Noexistingrights-of-wayorcorridorsareutilizedorparalleled.FromDevilCanyon,thecorridorleadseasttoWatana,thencenorthupDeadmanCreekanddownBrushkanaCreektoWellsCreek.ClimbingovertheWellsCreekpass(3,900feet),itdropsintoYanertForkandcontinuesonupDeanCreek.ThecorridorcrossestheDeanCreek-WoodRiverpass(4,000feet)andtravelsnorthalongtheWoodRivertoEster.28toLouisCreekandYanertFork.FromYanertForkthecorridorgoesoveranotherpass(2,900feet)toMoodyCreekandfollowsthiscreektoHealyandNenana-I.Theterrainvariesfromrollinghillsandvalleystohighpassesandsharpridges.Soilsvaryfrompoorlydrainedbottomlandtoexposedbedrock;permafrostisprevalent.Ecosystemscrossedaremoisttundra,alpinetundra,uplandspruce-hardwood,andmuskegandbog.Habitatsofmoose,caribou,andDallsheeparetraversed.Exceptfor22milesparallelingtheDenaliHighway,nootherrights-of-wayareparalleled.AlternativeNenana-4AlternativecorridorNenana-4is223mileslong,25mileslongerthanNenana-I.FromDevilCanyonitleadseastandnorth,eventuallytyingintoNenana-latHealy.Thelengthofthissegmentis126miles;'helengthofthecomparablesegn,ntofNenana-lis101miles.ThecorridorleavesDevilCanyon,headingeasttoWatanaDamsite,andthennorthupDeadmanCreekandBrushkanaCreektoWellsCreek.FromWellsCreekitheadsl:poverthepass(3,900feet)toLouisCreekandYanertFork,overanotherpass(2,900feet)toMoodyCreek,whichitfollowstoHealy.'Theterrainvariesfromrollinghillsandvalleystohighpassesandsharpridges.Soilsvaryfrompoorlydrainedbottomlandtoexposedbedrock;permafrostcanbeassumedtobeprevalent.Ecosystemstraversedaremoisttundra,alpinetundra,muskegandbug,anduplandspruce-hardwood.Habitatsofmoose,caribou,and')a11sheetarecrossed.Thereisnoparallelingofexistingcorridors.AlternativeNenana-5AlternativecorridorNenana-5is212mileslong,14mileslongerthanNenana-I.ItistotallyseparatefromNenana-I,beingaparallelcorridortotheeastofthepreferredcorridor.Noexistingrights-of-wayorcorridorsareutilizedorparalleled.FromDevilCanyon,thecorridorleadseasttoWatana,thencenorthupDeadmanCreekanddownBrushkanaCreektoWellsCreek.ClimbingovertheWellsCreekpass(3,900feet),itdropsintoYanertForkandcontinuesonupDeanCreek.ThecorridorcrossestheDeanCreek-WoodRiverpass(4,000feet)andtravelsnorthalongtheWoodRivertoEster.28 ThecorridorcrossesterrainvaryingfromtheflatTananaRivervalleytohighmountainpassessuchasWellsPass.SoilsvaryfrompoorlydrainedmaterialontheTananafloodplaintobarerockandtalusintheAlaskaRange.Permafrostisprevalent.Ecosystemscrossedarealpinetundra,moisttundra,uplandspruce-hardwood,lowlandspruce-hardwood,andbogandmuskeg.SignificantamountsofDallsheep,moose,andcaribouwinterrangeareencountered.AlternativeMatanuska-lAlternativecorridorMatanuska-ldiffersradicallyfromSusitna-linthatitloopstotheeastandsouth,andapproachesPointMacKenziefromtheeast.Itstotallengthis265miles,129mileslongerthanSusitna-1.Aconsiderableportion,125miles,parallelstheGlennHighwaycorridorandothersecondaryroadandexistingorplannedtransmissioncorridors.FromDevilCanyonthecorridorheadseasttoWatanaandVeedamsites,,,'entravelssoutheastoverasparselyforested,poorlydrainedplateautotheheadoftheLittleNelchinaRiver.Predominantlyrollinghills,theterrainisfairlyopenandgcmtle.ThecorridorpassesjusttothewestofSlideMountain,whereitturnswesttoparalleltheGlennHighway.OnceovertheTahnetaPassandintotheMatanuskadrainage,thecorridorleadswestthroughasharplydefinedvalleyflooredwithrollinghillsanddrainedbyastronglyincisedriver.Continuingwest,thecorridorencounterstheflatlandatthemouthoftheMatanuska""Heyandthediminutivefarmingareaofthelowervalley.ContinuingsouthwestalongthenorthernshoreofCookInletittraversesconsiderable,orestsandmuskegsontheflatlandsnorthofPointMacKenzie.Thesoilsencounteredvaryfromthepoorlydrained,finegrainmaterialsneartheLittleNelchinatogroundmoraineandgravelintheUpperMatanuskaValley,welldrainedgrayloamintheLowerMatanuskaValley,andpoorlydrainedpeatintheflatlandnortofPointMacKenzie.PermafrostiscontinuousfromVeedamsitetoTahnetaPass,discontinuousintheupperMatanuskaValley,andsporadicinthelowervalleytoPointMacKenzie.Thecorridorencounterstheuplandspruce-hardwoodecosystemsalongtheSusitnaRivertoVeedamsite,andmoisttundratotheLittleNelchina,anduplandspruce-hardwoodtothelowervalley.FromthelowervalleytoPointMacKenzie,bottomlandspruce-poplar,farmland,andbog-muskegareencountered.29ThecorridorcrossesterrainvaryingfromtheflatTananaRivervalleytohighmountainpassessuchasWellsPass.SoilsvaryfrompoorlydrainedmaterialontheTananafloodplaintobarerockandtalusintheAlaskaRange.Permafrostisprevalent.Ecosystemscrossedarealpinetundra,moisttundra,uplandspruce-hardwood,lowlandspruce-hardwood,andbogandmuskeg.SignificantamountsofDallsheep,moose,andcaribouwinterrangeareencountered.AlternativeMatanuska-lAlternativecorridorMatanuska-ldiffersradicallyfromSusitna-linthatitloopstotheeastandsouth,andapproachesPointMacKenziefromtheeast.Itstotallengthis265miles,129mileslongerthanSusitna-1.Aconsiderableportion,125miles,parallelstheGlennHighwaycorridorandothersecondaryroadandexistingorplannedtransmissioncorridors.FromDevilCanyonthecorridorheadseasttoWatanaandVeedamsites,,,'entravelssoutheastoverasparselyforested,poorlydrainedplateautotheheadoftheLittleNelchinaRiver.Predominantlyrollinghills,theterrainisfairlyopenandgcmtle.ThecorridorpassesjusttothewestofSlideMountain,whereitturnswesttoparalleltheGlennHighway.OnceovertheTahnetaPassandintotheMatanuskadrainage,thecorridorleadswestthroughasharplydefinedvalleyflooredwithrollinghillsanddrainedbyastronglyincisedriver.Continuingwest,thecorridorencounterstheflatlandatthemouthoftheMatanuska""Heyandthediminutivefarmingareaofthelowervalley.ContinuingsouthwestalongthenorthernshoreofCookInletittraversesconsiderable,orestsandmuskegsontheflatlandsnorthofPointMacKenzie.Thesoilsencounteredvaryfromthepoorlydrained,finegrainmaterialsneartheLittleNelchinatogroundmoraineandgravelintheUpperMatanuskaValley,welldrainedgrayloamintheLowerMatanuskaValley,andpoorlydrainedpeatintheflatlandnortofPointMacKenzie.PermafrostiscontinuousfromVeedamsitetoTahnetaPass,discontinuousintheupperMatanuskaValley,andsporadicinthelowervalleytoPointMacKenzie.Thecorridorencounterstheuplandspruce-hardwoodecosystemsalongtheSusitnaRivertoVeedamsite,andmoisttundratotheLittleNelchina,anduplandspruce-hardwoodtothelowervalley.FromthelowervalleytoPointMacKenzie,bottomlandspruce-poplar,farmland,andbog-muskegareencountered.29 ThesectionfromDevilCanyontotheheadoftheLittleNelchinaRiverrunsbetweenmajorcariboucalvingandwinteringranges.TheNelchinaherdnumberedover61,000inthelate1960's,presentlyithasbetween4,000and5,000animals.SomewinteringrangeiscrossedalongtheLittleNelchinatotheGlennHighwayandTahnetaPass.SomeDallsheephabitatexistsintheTahnetaPass;mooseconcentrationsareencounteredinthePointMacKenziearea.AlternativeMatanuska-2AlternativecorridorMatanuska-2is384miles,119mileslongerthanMatanuska-1and248mileslongerthanSusitna-l.FromWatanadamsiteitloopsmuchfurthertotheeastthanMatanuska-l,rejoiningitatSlideMountain;thissegmentofMatanuska-2is216miles,versus97miles,forthecomparablesegmentofMatanuska-l.FromWatanadamsitethecorridorcrossestheSusitnaRiver,headingJ'10rtheasttowardButteCreekaneltleDenaliHighway.RecrossingtheSusitnainthevicinityofDenahdamsite,thecorridorcontinueseast,crossingtheMaclarenRiverandstillparallelingtheDenaliHighwayuntilitapproachesFaxson.TurningsouthandcrossingtheGulkanaRiveratleasttwiceandparallelingtheRichardsonHighwayandtheAlyeskaPipeline,itheadstowardGlennallen.FromGlennallenthecorridorheadswestupthevalleyoftheTazlinaRiver,parallelingtheGlennHighwaytoSlideMountainandthejunctionwithMatanuska-l.111majorityoftheterrainisflatland;fromWatanatoDenalidamsitesecorridorencountershillyterraindissectedbylongvalleysandlowpasses.ThehighestpointonthiscorridorisintheTangleLakes-RockCreekareabetweentheMaclarenRiverandPaxson.Thisisaplateauofabout4,000feetelevation,poorlydrainedandcoveredwithpost-glacialfeaturessuchaseskersandterIninalmoraines,andmanysmalllak.es;perma-frostisprevalent.Thepredominantecosystemtothispointismoisttundra.FromPaxsontoSlideMountainthecorridorlieswithintheCopperRiver/lowlands,abasinunderlainbynearlycontinuouspermafrost.GenerallyVpoorlydrained,thisbasinisdominatedbyuplandandlowlandspruce-hardwood,andmuskegecosystems.ExceptfortheareaaroundGlennallen,thisentirecorridorrunsthroughthewinterrangeoftheNelchinacaribouherd.AlongtheCopper,GulkanaandTazlinaRiversaroundGlennallenmooseconcentrationsexist,andsmalle,-concentrationsareencounteredaroundWatanaandDenalidamsitesandtheTangleLakes.Almostallofthiscorridortraversesmediumdensitywaterfowlhabitat.30ThesectionfromDevilCanyontotheheadoftheLittleNelchinaRiverrunsbetweenmajorcariboucalvingandwinteringranges.TheNelchinaherdnumberedover61,000inthelate1960's,presentlyithasbetween4,000and5,000animals.SomewinteringrangeiscrossedalongtheLittleNelchinatotheGlennHighwayandTahnetaPass.SomeDallsheephabitatexistsintheTahnetaPass;mooseconcentrationsareencounteredinthePointMacKenziearea.AlternativeMatanuska-2AlternativecorridorMatanuska-2is384miles,119mileslongerthanMatanuska-1and248mileslongerthanSusitna-l.FromWatanadamsiteitloopsmuchfurthertotheeastthanMatanuska-l,rejoiningitatSlideMountain;thissegmentofMatanuska-2is216miles,versus97miles,forthecomparablesegmentofMatanuska-l.FromWatanadamsitethecorridorcrossestheSusitnaRiver,headingJ'10rtheasttowardButteCreekaneltleDenaliHighway.RecrossingtheSusitnainthevicinityofDenahdamsite,thecorridorcontinueseast,crossingtheMaclarenRiverandstillparallelingtheDenaliHighwayuntilitapproachesFaxson.TurningsouthandcrossingtheGulkanaRiveratleasttwiceandparallelingtheRichardsonHighwayandtheAlyeskaPipeline,itheadstowardGlennallen.FromGlennallenthecorridorheadswestupthevalleyoftheTazlinaRiver,parallelingtheGlennHighwaytoSlideMountainandthejunctionwithMatanuska-l.111majorityoftheterrainisflatland;fromWatanatoDenalidamsitesecorridorencountershillyterraindissectedbylongvalleysandlowpasses.ThehighestpointonthiscorridorisintheTangleLakes-RockCreekareabetweentheMaclarenRiverandPaxson.Thisisaplateauofabout4,000feetelevation,poorlydrainedandcoveredwithpost-glacialfeaturessuchaseskersandterIninalmoraines,andmanysmalllak.es;perma-frostisprevalent.Thepredominantecosystemtothispointismoisttundra.FromPaxsontoSlideMountainthecorridorlieswithintheCopperRiver/lowlands,abasinunderlainbynearlycontinuouspermafrost.GenerallyVpoorlydrained,thisbasinisdominatedbyuplandandlowlandspruce-hardwood,andmuskegecosystems.ExceptfortheareaaroundGlennallen,thisentirecorridorrunsthroughthewinterrangeoftheNelchinacaribouherd.AlongtheCopper,GulkanaandTazlinaRiversaroundGlennallenmooseconcentrationsexist,andsmalle,-concentrationsareencounteredaroundWatanaandDenalidamsitesandtheTangleLakes.Almostallofthiscorridortraversesmediumdensitywaterfowlhabitat.30 TheTangleLakesArcheologicalDistrict,andtheSourdoughInnontheRichardsonHighway,arelistedintheNationalRegisterofHistoricalandArcheologicalSites,publishedintheFederalRegisterofFebruary4,1975.WiththeexceptionofthestretchfromWatanatoDenalidamsites,allofMatanuska-2parallelsexistingcorridors.TheDeltaCorridorAlternativeTheDeltacorridoris280mileslong,82mileslongerthanNenana-I.ThiscorridorutilizesthecorridorthroughtheDeltaRivercanyonintheAlaskaRange,approachingFairbanksfromthesoutheast.FromDevilCanyonandWatanadamsitesthiscorridorheadseastoverthehillsnorthoftheSusitnaRiver,followingButteCreektoDenaliDamsite.ParallelingtheDenaliHighway,thecorridorre-crossestheSusitnaandfurthereast,theMaclarenRiver.OvertheplateaubetweentheMaclarenRiverandPaxsonthecorridorreachesacrestof4,000feet.AtPaxsonthecorridorturnsnort],followingtheRichardsonHighway-AlyeskaPipelinecorridoroverIsabelPass,awide,gentledivideat3000feetofelevation.NorthofthepassthecombmedcorridorspassthroughtheAlaskaRange,followingtheDeltaRiver.TherearesomeconstrictionsinthesouthernpartoftheDeltaRivercanyon;however,themajorityofthecanyonisnotoverlysevere.NorthofthecanyontheterrainconsistsofrollinghillsuntiltheTananaValleyisreached.ThetownsofBigDeltaandL,taJunction,bothsmallsettlements,areneartheconfluenceofthe'"'IeltaandtheTananaRivers.TheterrainintheTananaValleyisaflatfloodplaintothesouthwestoftheriver,androllinghillspunctuatedbyseveralmajortributariesonthenortheast.ThehillsonthenortheastflattenoutasthecorridorapproachesFairbanks.ThepredominantsoilsinthestretchfromWatanatoIsabelPassarepoorlydrainedpeatysoilswithshallowpermafrosttables.Shallow,rockysoilsdominatetheDeltaRivercanyonstretch,followedbymixedpoorlyandwelldrainedsoilswithlensesoffinegrainmaterial,generallyloess.MoisttundraisthepredominantecosystemfromWatanatoIsabelPass;theDeltaRivercanyonandthehillsnortheastoftheDeltaandTananaRiversaremostlywithintheuplandspruce-hardwoodecosystem.Alongthe31TheTangleLakesArcheologicalDistrict,andtheSourdoughInnontheRichardsonHighway,arelistedintheNationalRegisterofHistoricalandArcheologicalSites,publishedintheFederalRegisterofFebruary4,1975.WiththeexceptionofthestretchfromWatanatoDenalidamsites,allofMatanuska-2parallelsexistingcorridors.TheDeltaCorridorAlternativeTheDeltacorridoris280mileslong,82mileslongerthanNenana-I.ThiscorridorutilizesthecorridorthroughtheDeltaRivercanyonintheAlaskaRange,approachingFairbanksfromthesoutheast.FromDevilCanyonandWatanadamsitesthiscorridorheadseastoverthehillsnorthoftheSusitnaRiver,followingButteCreektoDenaliDamsite.ParallelingtheDenaliHighway,thecorridorre-crossestheSusitnaandfurthereast,theMaclarenRiver.OvertheplateaubetweentheMaclarenRiverandPaxsonthecorridorreachesacrestof4,000feet.AtPaxsonthecorridorturnsnort],followingtheRichardsonHighway-AlyeskaPipelinecorridoroverIsabelPass,awide,gentledivideat3000feetofelevation.NorthofthepassthecombmedcorridorspassthroughtheAlaskaRange,followingtheDeltaRiver.TherearesomeconstrictionsinthesouthernpartoftheDeltaRivercanyon;however,themajorityofthecanyonisnotoverlysevere.NorthofthecanyontheterrainconsistsofrollinghillsuntiltheTananaValleyisreached.ThetownsofBigDeltaandL,taJunction,bothsmallsettlements,areneartheconfluenceofthe'"'IeltaandtheTananaRivers.TheterrainintheTananaValleyisaflatfloodplaintothesouthwestoftheriver,androllinghillspunctuatedbyseveralmajortributariesonthenortheast.ThehillsonthenortheastflattenoutasthecorridorapproachesFairbanks.ThepredominantsoilsinthestretchfromWatanatoIsabelPassarepoorlydrainedpeatysoilswithshallowpermafrosttables.Shallow,rockysoilsdominatetheDeltaRivercanyonstretch,followedbymixedpoorlyandwelldrainedsoilswithlensesoffinegrainmaterial,generallyloess.MoisttundraisthepredominantecosystemfromWatanatoIsabelPass;theDeltaRivercanyonandthehillsnortheastoftheDeltaandTananaRiversaremostlywithintheuplandspruce-hardwoodecosystem.Alongthe31 Tananafloodplain,bottomlandspruce-poplarforestsarefound;localizedmuskeg-bogconditionsarefoundinthemouthsofSalchaandShawCreeks,andsomelowlandspruce-hardwoodoccursjustsouthofFairbanks.FromWatanatoPaxsonthewinterrangeoftheNelchinacaribouherdiscrossed.andfromnorthoftheDeltaRivercanyontojustsouthofBigDelta,bisonrangeiscrossed.Thebisonherdnumbersabout200animalsandistheresultoftransplantingefforts.Thecorridortra-versessporadicareasofmooseconcentration,thelargestoccuringalongtheTananaRiver.ThecorridoralsointersectsDallsheeprangeintheDeltaRivercanyon.Waterfowlhabitatalongthiscorridorisgenerallyoflowdensity,althoughlocalhigherqualityhabitatsexistnearDonnelly.ShawCreek,andSalchaRiver.TheareabetweenDonnellyandIsabelPassisoneofgoodtohighscenicquality,providinggoodviewsoftheAlaskaRange,particularlyoftheMt.Hayes-Skarlandgrouptothewest.Severalglacierscomewithinonetothreemilesofthecorridor;manyarevisiblefromthehighway.TheBlackRapidsGlacierisparticularlywellknownforitssurgingactivity.Thissamemountainousareaishighlymineralized,particularlywithcopperandgold.SomegoldoccursalsonearFairbanks.TheonlyothersignificantmineralresourcesnearthecorridoraretheareasSIthwestoftheTananaRiverwhichhavealowpotentialforoilandgas.Althoughattemptshavebeenmade,agricultureisnotsignificantanywherealongthiscorridor.Thisisduetoacombinationofproblemswithsoil,g"owingseasonlength.andwatersupply.TheforestsfromBigDeltatoFairbanksaremoderatelydenseandmaysupportasizeableforestry.32Tananafloodplain,bottomlandspruce-poplarforestsarefound;localizedmuskeg-bogconditionsarefoundinthemouthsofSalchaandShawCreeks,andsomelowlandspruce-hardwoodoccursjustsouthofFairbanks.FromWatanatoPaxsonthewinterrangeoftheNelchinacaribouherdiscrossed.andfromnorthoftheDeltaRivercanyontojustsouthofBigDelta,bisonrangeiscrossed.Thebisonherdnumbersabout200animalsandistheresultoftransplantingefforts.Thecorridortra-versessporadicareasofmooseconcentration,thelargestoccuringalongtheTananaRiver.ThecorridoralsointersectsDallsheeprangeintheDeltaRivercanyon.Waterfowlhabitatalongthiscorridorisgenerallyoflowdensity,althoughlocalhigherqualityhabitatsexistnearDonnelly.ShawCreek,andSalchaRiver.TheareabetweenDonnellyandIsabelPassisoneofgoodtohighscenicquality,providinggoodviewsoftheAlaskaRange,particularlyoftheMt.Hayes-Skarlandgrouptothewest.Severalglacierscomewithinonetothreemilesofthecorridor;manyarevisiblefromthehighway.TheBlackRapidsGlacierisparticularlywellknownforitssurgingactivity.Thissamemountainousareaishighlymineralized,particularlywithcopperandgold.SomegoldoccursalsonearFairbanks.TheonlyothersignificantmineralresourcesnearthecorridoraretheareasSIthwestoftheTananaRiverwhichhavealowpotentialforoilandgas.Althoughattemptshavebeenmade,agricultureisnotsignificantanywherealongthiscorridor.Thisisduetoacombinationofproblemswithsoil,g"owingseasonlength.andwatersupply.TheforestsfromBigDeltatoFairbanksaremoderatelydenseandmaysupportasizeableforestry.32 MatrixesforAssessmentofImpactsonCorridorSegments:Thefollowingmatrixesareforassessmentofimpactsofatransmissionlineby£ivecategories.ThedefinitionsofthecategoriesandgeneralinformationaregiveninAppendixI.Theprocessfromwhichthe22corridorsegmentsarederivedisexplainedonpages10-15.Duetotheproblemsattendanttoreducingsuchlargeamountsofinformationtosuchaconstrainedformat,itwouldappearthatsomeofthecategoriesarenottreatedonthesamelevelofdetailasothers.Specifically,climate,whichisaless-studiedandlessstablesituationthansoils.whicharetreatedonamoredetailedlevel.Onlydatathatwasfoundbysearchingtheliteraturewasentered.Thus,forexample,cariboumaybefoundinasegmentalthoughnomentionofitismadeinthematrix.Oneadvantagetothematrixsystemofpresentationisthatitiseasilyupdated;thus,discrepanciesbroughttoourattentioncaneasilybechanged.TheconstraintsofthisformatalsoobligetheUSeofabreviations:MMCPMzonestandsfortheMountMcKinleyCooperativePlanningandManagementzone;GVBAreferstotheGoldenValleyElectricAssocia-tion;MEAreferstotheMatanuskaElectricAssociation;andtheARRistheAlaskaRailroad.Thelandstatusentriesarebaseduponthelandstatussituationofl\iLLch1974.Stateselectionsrefertonotonlypatented,butalsoall.ndingandtentativelyapprovedStateselections.Nativevillagedpficienciesandregionaldeficiencies(NVDandNRD)willperhapsbethemostunstableareasatpresent,soitisquitelikelythattheentriesregardingtheselandsmaynotbepresentlyvalid.MatrixesforAssessmentofImpactsonCorridorSegments:Thefollowingmatrixesareforassessmentofimpactsofatransmissionlineby£ivecategories.ThedefinitionsofthecategoriesandgeneralinformationaregiveninAppendixI.Theprocessfromwhichthe22corridorsegmentsarederivedisexplainedonpages10-15.Duetotheproblemsattendanttoreducingsuchlargeamountsofinformationtosuchaconstrainedformat,itwouldappearthatsomeofthecategoriesarenottreatedonthesamelevelofdetailasothers.Specifically,climate,whichisaless-studiedandlessstablesituationthansoils.whicharetreatedonamoredetailedlevel.Onlydatathatwasfoundbysearchingtheliteraturewasentered.Thus,forexample,cariboumaybefoundinasegmentalthoughnomentionofitismadeinthematrix.Oneadvantagetothematrixsystemofpresentationisthatitiseasilyupdated;thus,discrepanciesbroughttoourattentioncaneasilybechanged.TheconstraintsofthisformatalsoobligetheUSeofabreviations:MMCPMzonestandsfortheMountMcKinleyCooperativePlanningandManagementzone;GVBAreferstotheGoldenValleyElectricAssocia-tion;MEAreferstotheMatanuskaElectricAssociation;andtheARRistheAlaskaRailroad.Thelandstatusentriesarebaseduponthelandstatussituationofl\iLLch1974.Stateselectionsrefertonotonlypatented,butalsoall.ndingandtentativelyapprovedStateselections.Nativevillagedpficienciesandregionaldeficiencies(NVDandNRD)willperhapsbethemostunstableareasatpresent,soitisquitelikelythattheentriesregardingtheselandsmaynotbepresentlyvalid. SUSITNACORRIDORSIMPACTSSOILSVEGETATIONWILDLIFEEXISTINGDEVELOPMENTSSCENICQUALITY/RECREATIONHighimpactonscenicquality-invadesDenali,StatePark.Linecanbeconcealedsomewhat,butwilltmdoubtedlyinterferewithpotentialtrailusers.Noexistingdevelopments-noimpacts.Routeopensupaninaccessiblearea;however,thisarealieswithinDenaliStateParkandisclosedtohtmting.Lowerelevationforestwillneedconsiderableclearing;regrowthratefastenoughtowarrantmaintenance.Uplandareaswillrequirelessclearingandmaintenance.Exceptforareaabovetimberline,vegetationhasahighrateofspreadoffireandahighresistancetocontrol.'Point}.!acKenzie-Talkc<::!naTalkeetna-GoldCreekviaTroublesomeCreek(2)DearthofsuitablesoiltypesonfloodplunWhole-area.~S__DOttomlaiid--~proce-.poplat,.exc:pt~structionofhabitatforsmallanimals.En-LittleimpactonscemcqualityfromNancytofloor-mostofareaispoorlydrainedfibrousforlocalmusk'eg,socons~derablecleanng~sbanfhb'f1manunaldtPt.M::Kenziesincelinecanbeconcealed.peat-vulnerabletofrostheavingbutwithneeded.Uplandvegetationhasafastenough•cemen~0/l.~~0\~rge~d bS~e~Somepossibleconflictswithprivatelandsfrom.Possibleconflict'nthrecreationareasinlowerosionpotential.Uplandsoilsarewellregrowthratetowarrantmaintenance,poorlymereaseproUChVl.ty0mtr.ucerusancdNancyLaketoTalkeetna.Noimpactonfore-Wasilla-BigLakeareaandNancyLakearea,d" d bt"b1t'dr·d"11bb1d1"tt1secondgrowth.Harassmentmhkelyduetogoseeableagriculture-mostsoilsaretmSuit-d drame,utmoresuscepJ.e0erosJ.on.ma~lJ.neareasWJ.proa yn~everyJ.ecoverthroughoutarea.FromNancyLaketoableforaiculture..epeninguponfinallocation.NoconflictPermafrostisabsent,discontinuous,ordeeplyinh~t:n~ce.Sl~shmustbe.d::-sposedof~oPt.McKenzie,accesswillbeimprovedifaccessgr.·withKnikarcheologicalsite.Talkeetnaburied,sothennaldisruptionisunlikely.NoJ.bJ.tmfestatJ.e:mofremammgtree~wJ.throadleftin;increasedhuntingpressuremaytoNancy:linecanbealmosttotallycon-majorrivercrossingsareanticipatedonthissl?ruceb:etleorJ.ps.beetle.VegetatJ.on~as.resultbutonlyadjacenttoclearing.·.cealedorlaidparallelandadjacenttoI------------troute.+hJ.W1resJ.stancetqfne<;:ontrol.-.'-'.'-~..:.:.-_t-:.:=:.:..=.:-=::...=:::.=::.::.-:.:-=::.:.::.::.="-..:..---+_---------------------l_existing:lineclearings.SomedesignproblemsinherenttosoilsaroundTalkeetna:Frostheaving,possiblepennafrost,poordrainage,slCMrevegetation.Uplandsoilsarewelldrained,buterosionpotentialishigher.PossiblerivercrossingneededforTroublesomeCreek,threeneededforSusitnaandTalkeetnaRivers.AccessroadcrossingonTroublesomeCreekmaycausesiltation.Talkeetna-GoldCreekviaAlaskaRailroad(3)Soilsinnorthernpartwelldrained,deeppemafrosttable;southernpartpoorlydrainedandsusceptibletofrostheaving.TalkeetnaRiveronlymajorrivercrossing;siltationhereisnotaproblemasrivercarriesglacialsilta~ready.Treeclearingneededalongentiresegment;maintenancewillbeneeded.Vegetationhashighrateofspreadandhighresistancetocontrol.Brushwillbeintroducedbyre-•.gro""th.NoextensivemaccessibleareasopeneduplineparallelsA.R.R.;accessroad'WOuldallowvehiclestoreachthisareaindepen-dentlyfromtheA.R.R.,sohtmtingpressuremayincrease.IftheA.R.R.right-of-""ayisadjournedorshared,impactswillbeverylow.IflineadjoinsAlaskaRailroad,railroadcouldbeelectrifiedandcorridorconsolid-ated.Lowimpactotherwise.l>~ditunimpactonscenicquality.MosttrafficthroughthisstretchisbyA.R.R.,andlinecanbehiddenwellfromraillinestmlesscor-.ridorisconsolidated.TalkeetnaRiver(4)Mixtureofpoorlydrainedsoilssusceptibletofrostheavingandpoorfotmdations,and""elldrainedsoilsonslopeslessapttocausepro-blems.Lowtomediumerosionpotential..Littlelikelihoodofseriouspermafrostdegra-,dation...ExPensiveclearingofheavyforestneededwithmaintenance.Brushwillbeintroducedbyregrowth.Vegetatianhashighrateoffirespreadandhighresistancetocontrol.Pioneerroute""illopenupnewareastoaccess.Huntingpressure""illincrease.Brushintro-ductioninthisareawillenhancehabitatsformoose!bear.Noexistingdevelopments-noimpacts.··Lowimpactonscenicquality.Lineisnotvis-ibleexceptfromair.Wildernessqualitysome-whatimpacted,buteaseofconcealmentkeepsimpac~10"".JisappointmentCreek(5)Lo""erosionpotentialbutpossibledegradation'orlocalpermafrost.Soilswelldrainedovermostofroute,shallo;...tobedrock.Fe""fore-seeableimpactsfromerosion,siltation,or,permafrostdegradation.~Clearingandmaintenanceneedinlowereleva-tions.Mostofrouteishighlandspruce-hardwoodandalpinetundra.Preservationofgroundvegetationessential-disruptioncanresultinlonglivedscarsduetoslowregrowthrate.Upperelevationshavehighrateoffirespread,1CMresistancetocontrol.Pioneerro~tewillopenupconsiderablenew.areastoaccess.Mostofthisareaisopen·foresttoalpinettmdra-damagetohabitatcouldbesevere(fromfires,erosion).Noexistingdevelopments-noimpacts.Linewillcrossopenalpinettmdraforquiteadistance,havinghighimpactonwildernessqual,ity.Impactonscenicqualityislowduetoinaccessibility.Prairit:Cn'el~-StephanLake([,)'Mostsoils""ell"drainedgravels;somepoorlydrainedareasnearStephenLake.Fe""fore-seeableimpactsfromerosion,siltationor.permafrostdegradation.HeavyforestclearingneededonTalkeetn~Rivervalley\vithattendentmaintenanceandintroductionofbrush.Lessclearingre-quiredandmorecareforvegetativematneededinPrairieCreekvalleytoStephenLake.Hightomediumrateoffirespread,hightomediumresistanceto~ontrol.Pioneerroutewillopenupconsiderablenewareastoaccess.Impactwillbelessonupperareasduetolessdisruptionofvege-tationbyclearing.Areaispresentlyac-cessiblebyfloatplaneandreceivedcon-Isiderablehtmtingpressurealready..Access.roadwillprobablynotbeusedbymosthunters.•P ..WherelineemergesfromTalkeetnaRi~ervalley.nvatelandand/orcabmleasesonlakeshorestoStephenLake,scenicqualityreceivesmediitnmthepassareas.Most.ofthesecan.be.impact;lakesreceivedsomerecreationaluse.avoided.Otherwise,nolmpactsoneXJ.stl11gImpactonlrildernessismeditunduetothedevelopments.existingrecreationaluseandeasyaccessibil-itybyfloatplane.DevilCanyon-GoldCreek(7)Welldrainedgravelsoilsldthlowtomedium:rosionpotentialanddee~permafrosttable,J.~any:Fe""foreseeablelmpactsfromerosion,s~ltatJ.onorpermafrostdegradation.Clearingofmediumforestwithperiodicmain-t:nance.Highrateoffirespread,mediumre-sJ.stancetocontrol.M::loseandbearhabitatenhancedbyregrowthonclearings.Accessroadmayresultin.increasedhtmtingpressure.OldjeeproadeXists~connectingDevilCanyonDamsitetoAlaskaRailroad.Miningclaims,nolongeroperating,onPortage.Creek.Theseroadscouldbepartoftheaccessroadsystem.Lo""impactonscenicquality-thisareaisnotpresentlyeasilyaccessible,andDevilCan-yonDamsiteroadwillnotbeusedmuchbynon-projectpersormel;linecanbeconcealedfromthisroadorcanbeusedasthelineaccessroadalso.De"-ilCanyon-StephanLake(8)Welldrainedgravelsoilswith10""tomedium.:rosionpotentialanddeeppermafrosttable,'ii!any.Fell'foreseeableimpactsfromerosion,sJ.ltationorpermafrostdegradation.Clearfugofmediumforestinrivervalley;lessclearingneededonplateau.Firerateofspreadinvalleyhigh,resistancetocon-trolmedium.Plateaurateofspread10"",resistancetocontrolhigh.Littleimpactonhabitatoflargemammalssuchasmooseandbear,minimalclearingonplateauareasandcreekcanyonscanbe.spanned.Ac-.cessroad\I'ouldbetmdercontrolfromdam-sitesounauthorizeduseforhmtingll'ouldbe10"".Noexistingdevelopments.Po""ersite""ith-dra""alforDevilCanyonReservoir.Possible·useofedgeof\otithdrml'alforright-of-way.Lo""impactonscenicquality-areaisofmed-iumscenicquality.SomerecreationaluseinStephenLakearea.Linecanbepartiallycon-cealedbutnottotally.StephanLake-Watana(9)Welldrainedgravelsoilsandpoorlydrainedsoils""ithvariablepermafrosttable.Fe""erosionimpactsbutpossiblepermafrostdegYadationandfrostheavinginpoorlydrainedsoils.Heaviervegetationincreekbottomscanbespannedoverbyline.Vegetationonplateauishighbrush,andlowbrushbay,neitherof.""hichrequireextensivecleaning.Rateoffut'spreadlow,resistancetocontrolhigh.Littleimpactonhabitatofmooseandbear,minimalclearingonplateauareasandspan-ningofcreekcanyons.Accesswuldbe.tmdercontrolofdarnsitessotmauthorizeduseforhtmting""auldbelow.Noexistingdevelopments.Po""ersitell'ith-drawalforDevilCanyonReservoir.Possibleuseofedgeofwithdrawalfor.right-of-way.Mediumimpactonscenicquality-areaisofmediumscenicquality.SomerecreationaluseofStephenLakearea.LinecanbeparMtiallyconcealedbutnottotally.35SUSITNAIMPACTS SOILSVEGETATIONNENANACORRIDORSIMPACTSWILDLIFEEXISTINGDEVELOPMENTSSCENICQUALITY/RECREATIONShallowslopesandgravellysoilswillreduceSuccessivelylessclearingasi1egmentgoesEntiresegment,."ithinMt.McKinleyCoopera-erosionimpacttolowlevels.Shallowperma-north.InBroadPass,notreesneedSomeenhancementofbearandmoosehabitatfrostinpoorlydrainedareassusceptible~oclearingandtheonlyvegetationlostinsouthernpartofsegment;nochangeinFewprivateholdings-smallchanceofcon-tivePlanningandManagementZone.SouthernGoldCreek-Cantwelldegradation;sincetheaccessroadcanavo~dwouldbefromaccessroad.Slowregrowthnorthernpart.ThisrouteopensupnofHct.Lowimpact-veryfewexistingpartbordersDenaliStatePark.Visibleline(0)theseareas,thisimpactwillbelow.impliesthatmaintenancewillnotbeneededmajornewareastohtmting;overallimpactdevelopments.willhavehighimpact,particularlyiftowestandalsothatrevegetationmaybenecessaryislow.ofhighwayandrailroad.Linecanbecon-alongsomeareas.~1ediumtohighrateofcealedsomewhat,however,inmostofsegment.firespread;highresistancetocontrol.BroadPasshasleastcoverforline..\\heretheaccessroadcrossesshallowslopes,Clearingvariesfromdensespruce-hardwoodsSomeenhancementofbearandmoosehabitatithasahighprobabilityofcrossingpoorlytoalpinettmdra.~mstvegetationlossinheavierforestedareas.butnosignifi-iowimpactonscenicquality;thisarea·isdrainedloamwithsurfacepeatandshaHOI'"willbefromaccessroad.Slowregrowthcantchange.AccessroadopensupaJpre-ofmediumscenicqualityandnotreadilyWatana-WellsCreekvipermafrost.ImpactonpermafrostinthisimpliesthatmaintenancewillnotbeviouslyinaccessibleareatointrusionNoexistingdevelopments-noimpacts.accessible.However,thereisahighim-BrushkanaCreek(11)caseishigh,andfrostheavingispossible.neededandthatinplacesrevegetationandhtmtingjsincecaribouandmoosearepactonwilderness,especiallyifanaccesspresent,thiscouldhaveasignificantUplandsoilsarewelldrainedwithdeepmaybenecessary.~fedituntohighrateofimpactonhtmtingpresenre.Firingonroadisbuilt.permafrost,soimpactislowonpermafrost,firespread;highresistancetocontrol;ttmdraareascouldseverelyimpactcari-meditunonerosion.lowresistanceinalpinettmdra.bouhabitat.ShallowslopesandgravellysoilswillreduceClearingvariesfromspruce-hardwoodstoSomeenhancementofbearandmoosehabitaterosionimpacttolowlevels.Shallowperma-highbrush.~bstvegetativelossfromac-inheavierforestedareas,butlittlesigni-ApartfromsettlementsalongDenaliHighway,Meditunimpactonscenicquality;areaisofWellsCreek-Cantwellcessroads.SlowregrOl'lthimpliesthat(12)frostinpoorlydrainedareassusceptibletomaintenancewillnotbeneeded.MedituntoHcantchange.Nonewareasopenedup.nodevelopments-noimpacts.highscenicquality,butlinecanbecon-degradation;sincetheaccessroadcanavoidcealed.EntiresegmentwithinlIioIPCFNZone.theseareas,thisimpactwillbelow.highr.ateoffirespread;highresistanceOverallimpactis101"'.tocontrol.Higherosionpotentialthroughoutentire.stretch.Exposedbedrockincanyonswillpro-HeavyclearinginvalleybottombyYanertSomehabitatdestructionand enhancementdueTheadditionof'athirdright-ofwaythroughvidesolidtowerfoundationsbutwillinhibitFork;lighterclearingthroughoutrestoftoclearing;overallimpactofclearingisSevereimpactonscenicqualityjnotonlyisCantwell-Healy(3)accessroadconstructionifneededoncanyonroute.Highrateoffirespread,highre-10''''.Nonewareasopeneduptohtmting.thecanyonsmaycausecongestionunlessthecanyonanareaofhighscenicquality.slopes.Poorlydrainedareashavemediumsistancetocontrolonvalleyfloor;lowConstructionactivitiescombinedwithtrans-rights-of-wayareconsolidated.Possibleconcealmentofthelineishardandthewestpennafrostdegradationsusceptibility.Activeresistanceinalpinetundra..portationuseofcorridormaytemporarilyconnectiontoGVEDlineatHealy.bankoftheNenanaisparkland.faultnearHealy;DenaliFaultcrossesnearrepUlsesomemammalssuchaswolfandbear.Windy.CrossingofNenanaRivernecessary.HigherosionpotentialandexposedbedrockonHeavyclearingonvalleybottomstonoConstructionactivitiesmayinhibitcaribouLowimpacttoscenicqualityduetothein-slopes.Someareasofpoorlydrainedsoil~learinginalpinetundra.Slowregrowthandsheepactivities.Overallhabitatmodi-accessibilityofthisotherwisehighlyscenicVIellsCreek-Deansusceptibletopennafrostdegradationin~nhigherelevations.Highrateoffireficationlow,especiallyifwinterroadsarea.Highimpacttowildernessquality,butwidervalleyfloors.DenaliFaultcrossesspread;highresistancetocontrolatand/orhelicopterconstructionisused.Noexistingdevelopments-noimpacts.limitedtothemediatevalleyoccupiedbyCreek(4)WellsCreek.CrossingofNenanaRivernec-lowerelevations;lowresistancetocon-Firecanseriouslyimpactsleepandcaribouline;natureofterrainwilladequatelycon-essary;rivertoodeepforfordingandistrolinalpinetundra.habitat.Largenewareaopenedbyaccessceallinetmlessitisnmonridges(tm-silt-ladennormally,sosiltationwillhaveroadwillincreasehuntingpressure.likelyinthissegment).lowimpact.High'erosionpotentialonslopes;highsus-HeavyclearinginYanertFork;ConstructionactivitiesmayinhibitcaribouLowimpacttoscenicqualityduetotheceptibilitytopermafrostdegradationonlittletonoandsheepactivities.Overallhabitatmodi-inaccessibilityofthisotherwisehighlypoorlydrainedvalleyfloors.Towardsclearingelsewhere.SlowregrOll'thinhigherficationlow,especiallyifwinterroads/PossiblelineconnectionatHealyPowerscenicarea.Highimpactto,."ildemessDeanCreek-Healy(5)Healy,welldrainedsoilsaresubjecttoelevationsandpoorlydrainedareas.Highhelicopter·constructionisused.FirecanPlant-UsibelliMineroadsmaybeusedqualityexceptforlower~kJodyCreekmeditunerosionpotentialandlowsuscepti-tolowrateoffirespread;hightolowforaccess.-(VsibelliMineworks).Natureofterrainbilitytopennafrostdegradation.Activeresistancetocontrol.seriouslyimpactsheepandcaribouhabitat.\\IillconceallineexceptforridgealongfaultsnearHealy.CrossingneededonHealyLargenewareaopenedbyaccessroad'WilllowerMoodyCreekwhereline,."illbesil-.Creek.increasehuntingpressure.houetted.Nenanafloodplainhasmeditunerosionpoten-.Clearing\\Iillenhanceconsiderableamount~Privateholdings(claims,homesteads,etc.)NoimpactonDryCreekarcheologicalsitetial.Poorlydrainedareassubjecttopoten-Heavyclearingformostofrouteexceptalongroute-townsofHealy,Lignite,sinceline''''illtraveloneastbankofNe-moosehabitat.Caribouconfinedtowest.Nenana:Thesetownsmaybeaffectedbytialpennafrostdegradationandfrostheaving.nearHealy.IntroductionofbrushintobankofNenanaandthuswillnotbeaffectednanaRiver.!'<lediumimpactnearHealyandHealytoEster(6)Goldstreamhillsarefine-grainwithright-of-way.Highrateoffirespread;iflinerunsoneastbank.None\\lsignifi--constructionactivitiessincetheyareintheGoldstreamHills;10\\1impactalongandarehighlyerosiveandsusceptibletohighresistancetocontrol.transportationcentersalongthesegment.lowerNenanaRiver.Impactwillbelesspennafrostdegradationandslopeinstability.cantareasopenedup,particularlyifGVEAIfGVEAlineisadjoined,therewillbeaifGVEAright-of-wayisadjoined.Lowim-CrossingofTananaRiverneeded.right-of-wayisparalleledoradjoined.conflictwiththeFAAairportatNenanaforpactonwilderness.clearance.~UpperWoodRiver:lowerosionandpermafrostHeavyclearingonTananalowlands.LighttoConstructionactivitiesandfireinUppe~Lowimpactonscenicqualityduetoextremeimpacts.LowerWoodRiver:mediumtohighnoclearinginUpperNoodRiverinalpineWoodRiver''lillnegativelyaffectcaribouandNoexistingdevelopmentsinaccessibility.WildernessqualitywillDeanCreektoEst~rpotentialimpactsonpermafrost.Highsus-andmoisttundra.andtheTananafloodplainsheep.ClearinginLowerWoodRiverwillen--noimpact..receivehighimpactinupperWoodRiver,(\VoodRiver)(17)ceptibilitytoheaving.La,."tomeditunero-JIR.lSkegs.VaryingratesoffirespreadandhanceJI\Oosehabitat.VerylargeareaopenedmedituntolowalonglowerNoodRiverbe-sionpotential.CrossingofT~anaRivercontrollability.upbyaccessroadwillbe5ubjectedto.causeofvaryingconcealmentandpresenceneeded.greaterhuntingpressure.ofcivilization..36NENANAIMPACTS nATIONoughoutsegment;noneedssibledisruptionofequenterosiononslopesationonpoorlydrainedowtomediumresistance'axsontoDonnellyDome~asroutegoesnorth.1clearingsinSpruce-lashmustbedisposedofcestations.Vegetation.teoffirespreadand:ancetocontrol.Impacts;ifAlyeskaright-of-waynostofroute;someclear-.rdwoodsnecessaryaround•River.Riskofbeetle.VegetationonUpperlowtomediumrateoffirehighresistancetocon-lowerLittleNelchinahasandhighresistanceto,ringthroughoutsegment.,illoccurinclearings.tationofslash.Vege-offirespreadandhigh,l.Overallimpactswould:aright-of-wayweretobeIe.DELTAANDMATANUSKACORRIDORSIMPACTSWILDLIFEConstructionactivitiesmayinterferewithcariboumovements.Lowimpactonmooseactivities.Littlechangeinhab~tatfromconstruction,unlesssevere~carrlngorex-cessivefiresaffectvegetat1on.AccessroadwillopenuptheButteCreekareaandhootingpressuresmayincrease.Possibleinterferencewithcaribouandbisonmovements.Lowimpactonmooseinsouthernpart,butwillenhancehabit';-tonmoreheavilyforestedareas.Low~act.onDallSheepinDeltaCanyonsinceIme,nIlstaylow.Minimaldestructionofduckhabitatifright-of-waycrossesSa~cha~lou¥hsandpondsbyDonnellyDome.S,ltatlonmGul-kana,SalchaandSha,,,creekswillaffectanadromousfish.Possibleinterference\VithNelchinacaribouherdmovements.La\VimpactonmooseexceptonlowerLittleNelchina,\Vhereclearings\Villenhancecaribouhabitat.Thisrouteopensaverylargeareatohunting.Possibleinterference\VithNelchinacaribouherdmovements.AIthoughmoosearemnnerous,majorimpactshouldbetheenhancementofhabitatalongclearings.Fire\Villbedestructivetocaribouhabitat,mayenhancemoosehabitat.Overallimpacts\VouldbelessiftheAlyeskaright-of-\Vayweretobeadjoined.EXISTINGDEVELOPMENTSNoexistingdevelopmentsexceptforscarcesettlementsalongDenaliHighway.Noimpact.SettlementsalongRichardsonHighwaymaybeimpactedbylineright-of-way.acquisiti?n.TownsofDeltaJunctionandB1gDeltaw1llreceivesomeimpacts,mostlybeneficial,.fromtransitofmaterialandlabor.POSS1-blecongestionofright-of-waythrough.DeltaCanyonunlessrights-of-wayar:consol1dated.Overallimpactswouldbeless1fAlyeskaright-of-wayweretobeadjoined.TheprobabilityofconstructionofVeeDamisincreasedbyroutingatransmissionlinebythedamsite.TownofGlennallen\ViIIreceivesomeimpacts,mostlybeneficial,fromtransitofmaterialandlabor.Noothermajorimpacts.Overallimpacts\VouldbelessifAlyeskaright-of-\Vay\Veretobeadjoined.SCENICQUALITY(RECREATIONHighimpactsonscenicqualityfromP~ontoDonnellyDome,mediumtoDelta~unctlon,andlowtoEielsonA.F.B.Impact1Safunc-tionofexistingscenicqualityandabilitytoconcealthetransmissionline.Iftrans-missionlineisroutedparalleltoRichardsonHighway,recreationareasandhist?ricsiteswillbenegativelyaffected.IfImead-joinstheAlyeskaright-of-way,impactswillbeless.Lo\Vimpactsonscenicqualityduetomedium-highexistingscenicqualityofveryinac~essiblearea.Totheeastto\VardsLakeLaUlse,impact\Vouldbehigherbecauseofgreateraccessibility.Wildernessqualitysufferssincethis\Vouldbeapioneercorridor.Lawimpactonscenicquality-linecanbeeasilyconcealedforentiresegment.P?S-sibleconflicts\Vithrecreationalandh1S-toricsitesdependingonfinallocation.Impacts\VouldbelessifAlyeskaright-of-\Vay\Veretobeadjoined.'assandGunsightMountain'edmediumtoheavyclear-h.Brushintroductionngs.ClearingswillneedRiskofbeetleinfest-etationhasmediumto,readandhighresistanceLo\VimpactonDallSheep.hancemoosehabitat.Lawingeneral.Clearingwillen-impactson\VildlifeConsiderablefarmingcommunityonPalmer-conflictsmayariseinlanduse.Roadsbyabandonedcoalmineareascanbeusedasaccess.La\VerMatanuskaValleyhasahighratioofprivatelyownedlandwhich\Villresultinacquisitionforright-of-\Vay.SevereimpactonscenicqualityofUpper.MatanuskaVaneyandTahnetaPass.Partlalconcealmentispossible.Impactlessensasvalley,;idens,andagriculturalusebecomesmoreapparentandconcealment~creases..La\VimpactonKnikArmarea;ImecanaVOldallrecreationareasandbeconcealedfromroads.37DELTA/MATANUSKAIMPACTS SOILSVEGETATIONDELTAANDMATANUSKACORRIDORSIMPACTSWILDLIFE.'Constructionactivitiesmayinterferewi1ConsiderableareasofshallowpermafrosttableHinimalclearingthroughoutsegment;noneedcariboumovements.Lowimpactonmoosesoilswithconsequentvulnerabilitytodegrada-formaintenance.Possibledisruptionofactivities.LittlechangeinhabitatfreWatanatoPaxsonviation.Low-lyingareasarepoorlydramedan~surfacematandsubsequenterosiononslopesconstruction,unlessseverescarringor(ButteCreek(8)susceptibletoheavingandsettlement.Ero~10rorpermafrostdegradationonpoorlydrainedcessivefiresaffectvegetation.Accesspotentialismediumtohigh.Accessroadw111areas.Fireshavelowtomediumresistanceroadwillopenupthe~utteCreekareaa:rneedtobeadequatelyculvertedoverareasoftocontrol.poordrainage.huntingpressuresmay1ncrease.LightclearingfromPaxsontoDonnellyDomePossibleinterferencewithcaribouandbiSoilvariesfromshallowcontinuouspermafrostmovements.Lowimpactonmooseinsouthetofrostfreesoils,withmediumtohighero-area.Heavyclearingasroutegoesnorth.part,butwillenhancehabitatonmoresionpotential.SoilinDeltaCanyonveryBrushintroductioninclearingsinSpruce-heavilyforestedareas.LowimpactonDalPaxsontoFairbanks(19)thin,sobedrockiseasilyreachedfortowerHardwoodforests.SlashmustbedisposedofSheepinDeltaCanyonsincelinewillstafoundations.Thixotropicsiltsnorthoftopreventbeetleinfestations.Vegetationlow.MinimaldestructionofduckhabitatSummitLakecombinedwithseismicriskwill.hasmediumtohighrateoffirespreadandifright-of-waycrossesSalchasloughsanhaveaneffectonline.PhelanCreek,Tananahightomediumresistancetocontrol.ImpactspondsbyDonnellyDome.SiltationinGulRiver,GulkanaRiver,ShawandSalchaCreeksoverallwouldbelessifAlyeskaright-of-waykana,SalchaandShawcreekswillaffectneedcrossings.weretobeadjoined.anadromousfish.LowareaspoorlydrainedLightclearingovermostofroute;someclear-Continuouspermafrost.ingthroughSpruce-HardwoodsnecessaryaroundPossibleinterferencewithNelchinacarllWatanatoSlideMtn.andvulnerabletoheaving.MediumerosionlowerLittleNelchinaRiver.Riskofbeetleherdmovements.Lowimpactonmooseexc,viaVee(20)potential.Considerableimp~cttopermafro~tinfestationofslash.VegetationonUpperonlowerLittleNelchina,whereclearing,possiblefromaccessroad;'.....mterconstructlonSusitnaplateauhaslowtomediumrateoffirewillenhancecaribouhabitat.Thisrout,preferable.Accessroadwillneedtobe.ade-spreadandmediumtohighresistancetocon-opensaverylargeareatohunting.quatelyculvertedoverareasofpoordramage..trol.VegetationonlowerLittleNelchinahas.highrateofspreadandhighresistancetocontrol.Continuouspermafrost.L01'areaspoorlyPossibleinterferencewithNelchinacarib<drainedandvulnerabletoheaving.MediumMediumtoheavyclearingthroughoutsegment.herdmovements.Althoughmoosearenumer,erosionpotential.ConsiderableimpacttoBrushintroductionwilloccurinclearings.majorimpactshouldbetheenhancementofPaxsontoSlideMtn.permafrostpossiblefromaccessroad;1'linterRiskofbeetleinfestationofslash.Vege-habitatalongclearings.FirewillbeviaGlennallen(21)constructionpreferable.Accessroadwilltationhashighrateoffirespreadandhighdestructivetocaribouhabitat,mayenhan'needtobeadequatelyculvertedinareasofresistancetocontrol.Overallimpactswouldmoosehabitat.Overallimpactswouldbe'poordrainage.OverallimpactswouldbebereducedifAlyeskaright-of-wayweretobelessiftheAlyeskaright-of-waywereto,reducedifAlyeskaright-of-wayweretobeadjoinedwerepossible.beadjoined.adjoinedwherepossible.~~tanuskaValleysoilshavemediumtohighExceptforTahnetaPassandGunsightMountainerosionpotential;impactfromconstructionandarea,segmentrequiredmediumtoheavyclear-LowimpactonDallSheep.ClearingwilleSlideMts.toPointaccessroadcanbehigh.Permafrostdegradationingforentirelength.Brushintroductionhancemoosehabitat.Lowimpactsonwildlis,unlikely.KnikArmsoilshavelowerosionIwilloccurinclearings.ClearingswillneedMacKenzie(22)potential,soimpactof,constructionandroadperiodicmaintenance.Riskofbeetleinfest-ingeneral.willbelow.Permafrostdegradationisunlikelyationofslash.Vegetationhasmediumtobutfrostheavingisveryprobableinpoorlyhighrateoffirespreadandhighresistancedrainedareas.tocontrol. ENVIRONMENTALIMPACTSOFCORRIDORSImpactsofPreferredCorridorSusitna-lSoils:InthelowerSusitnaValleythecorridorwillencountersubstantialareasofpoorlydrainedsoilsthatalthoughnotvulnerabletoerosionwill,however,posetheproblemoffrost-jackingoftowerfootingsandanchors.Unlessmeasuresaretakentocounteractthispotentialproblem,additionalmaintenanceanditscorrespondingimpactswillbenecessary.Thebetterdraineduplandsoilsarelessvulnerabletoheaving,but,aswithmanyfloodplainsoils,israthersusceptibletoerosion,particularlystreamerosion.Sincetherelativeproportionsofthesetwosoiltypesvaryfrompoorlydrainedsoilsinthesouthernportiontowelldraineduplandsoilsinthenorthern,theimpactsassociatedwiththemwillhaveasimilardistribution.Accessroadconstruction,althoughrequiringheavyclearing,willberelativelyeasyintheuplandsoils.Watererosionwilloccursomewhat,particularlyduringtheconstructionphase,influencingwaterqualityintheclearwaterstreamscrossed.Roadconstructionintheareasofpoorlydrainedpeatswilli.llvolveproblemsofhardeningthesurfacesufficientlytobearconstructiontraffic.Ruttingandgougingoftrackswilloccurifconventionalvehiclesattempttocrossanunhardenedsurface.Corduroy,piles,deepfills,anddrainagearemethodsofhardeningmuskegsurfaces,allofwhichareexpensiveandwillinvolveIe·1impacts.Avoidanceoftheproblembycarefulrouting,wintercon-e'ruction,and/oruseoflow-pressuretreadvehicleswillinvolvelessj,iLpacts.Permafrostisgenerallynotpresent.Whereisolatedmassesdoexist,theyareburiedfairlydeeply.Potentialthermaldisruptionofperma-frostalongthiscorridorisunlikely.ThecorridorparallelstheSusitna,involvingnocrossing,butinter-sectsseveraltributariesfromtheTalkeetnaMountains.Fordingofmachineryandyardingoflogsacrossthesestreamswillresultinincreasedsiltation.Inthesmallerclearwaterstreamsthismayresultinreductionofspawninghabitatandpotentialgilldamageinfishdown-streamofthecrossing.Vegetation:IfthelinetoPointMacKenzieis345kv,theamountofclearingfortheright-of-waywillbeupto2,308acres;ifthelineistobe230kv,theamountofclearingwillbeupto2,060acres.Theactual38 clearingwillprobablynotbeashighastheseacreagessincevegetationalongsomestretchesmaynotrequireclearing,exceptaroundtowerbases.Theterrainbeingrelativelyflat,theaccessroadcanutilizetheright-of-waywithoutadditionalclearing.Theimmediateeffectofthisclearingwillbethedestructionofthevegetation;themuchmoresignificantimpactwillbeuponerosionandwildlifehabitats.Inhillyterrainmechanicalclearingmethodssuchasbulldozingwillcauseconsiderabledisruptionofthesoilandsubsequenterosionandstreamsiltation.Theuseofbrushbladeswillreducethiseffect.Onsteepslopeshandclearingwillmitigatetheotherwiseheavyerosionpotentiallikelywithmechanicalclearing.Toreduceavailablefuelforforestfires,andtoreducepotentialinfesta-tionofhealthytreesbysprucebeetles(Dendroctomusrufipennis)andipsbeetles,slashmustbedisposedof.Thiscanbeeitherbysaleofmarketabletimberorbyburning.Althoughburningwillreduce,,;rqualitytemporarily,itismoreeconomicalandlessdamagingthanthealternatives.(SeeMitigatingMeasures)RegrowthratesalongthiscQrridorarefastenough,particularlyinthesouthernportion,towarrantperiodicsuppressionoftallgrowingtreeswhichposeahazardtothetransmissionline.Thepreferredmethodalongthiscorridorismanualapplicationofasuitableherbicide.Theamountofclearingtobemaintained,themodestregrowthrates,andhighcostoflabormakethisalternativepreferrableinthiscorridoroveraerialapplicationofherbicidesontheonehand,orhandcutting.residualtreesontheother.Ifproperapplicationtechniquesareadheredto(seeMitigatingMeasures),therewillbenootherimpactsotherthanthemaintenanceofasub-climaxvegetation.Accidentaloversprayingorwinddrift,orimproperdilutionresultinginunneces-sarydestructionofvegetation,andsprayingofwaterbodiesresultinginhabitatdestructionforaquaticlifeisnotlikelytooccurwithmanualapplication.Sectionsneedingvegetationsuppressionoccursinthebottomlandspruce-poplar,lowlandspruce-hardwood,anduplandspruce-hardwoodforests,particularlyinthebottomlandspruce-poplarandmuskeg-bogareas,whichcomprisesasignificantproportionoftheecosystemscrossedbythiscorridor,willneedlittleclearingandnovegetationsuppression.Lowlandspruce-hardwoodareaswillnotneedtobemaintainedasoftenasbottomlandspruce-poplar.39 Wildlife:Alterationofvegetationpatternswillaffectwildlife.Thiscorridortraversesmanyareasofmooseconcentration,andmooseshouldbenefitfromtheintroductionofbrushresultingfromtheregrowthontheclearing.Sincetheclearingmustbemaintained,thisbrushareawilllastforthelifeoftheline.Mostbrushareasareintransition,changingfromthebrushphasetosomeotherphasenearertheclimacticphase;thebrushinatransmissionclearingcanbecountedasamorepermanentsourceofbrowse.Animalsdependentuponclimacticforest,suchassquirrels,willsufferlossanddisplacement.However,theirfasterreproductiverateswillallowtheirpopulationstoadjustrapidly.Mostanimalswillbenefitfromtheedgeenvironment,offeringbothforageandcoverfortheadjacentforestandbrush.Initially,animalmovementsmayoccuralongtheright-of-way,butasthebrushgrowsintoadensecoverthiswillbelimited.Inanyevent,thisimpact"houldbelowinthiscorridor.Constructionitselfwillaffectwildlife.Largermammalsmaytemporarilyleavetheareatoreturnaft",rtheconstructionactivity.Smalleranimalswillsufferlossofindividuals.butshouldrecuperaterapidlyonceconstructioniscompleted.Thedensityofforestinthiscorridorwillallowanimalstomoveonlyashortdistancetoavoidcontactwithconstruc-tionactivities.Vegetationsuppression,bywhatevermethod,willperiodicallyremove_',JVerfromalongtheright-of-way.However,duetothesurroundingcoveroftheunclearedforests,thisimpactwillbeinsignificant.Recreation:TheSusitna-lcorridorwillapproachwithin10milesofseveralrecreationalandwaysideareasinthelowerSusitnavalley.ThelargestoftheseistheNancyLakesRecreationArea.Inaddition.thecorridorwillrunadjacenttotheDenaliStateParkfor22miles.However.theSusitnaRiverwillseparatethecorridorfromthePark;t..':lemainaccesstolandswithintheParkistheAnchorage-FairbanksHighway,andthisisanaverageof10milesawaytothewestovera2,000to2,500feethighridge.Dependinguponthepoliciesofthelandmanagingagenciesinvolved,thiscorridorwillprovideaccesstoareaspreviouslydifficultofaccess.ThelargestsuchareaisthatsouthofNancyLaketoPointMacKenzie.Denseforestandmuskeglimittravel.AserviceroadwouldallowaccessforLunters,boaters,andcampers.40 CulturalResources:TheNationalRegisterofHistoricandArcheo-logicalSiteslistsonlyonesiteinthearea,KnikVillage.Thecorridorwillrunatleast10milestothewestofthissite.Itislikelythatarcheo-logicalsiteswillbefoundalongthecorridor,eitherduringthelocationsurveyorduringconstruction.Ifso,minorrouterelocations,orcarefultowerlocations,willprotectthesesites.Inadvertentalterationofasitewillreduceordestroyitshistoricalvalue.ScenicResources:Thiscorridordoesnottraverseanyareasofgoodorhighqualityscenicvalues.Thenorthernportionis,however,morescenicthanthesouthernportion.Inthenorthernportionthefairlycontinuousmoderatelydenseforestwillprovideamplescreeningfromtransportationroutes.Furthersouth,theforestsaremoreinterming-ledwithopenmuskeg.Glimpsesofthetransmissionlinecanthenbeseenfromthehighwayorrailroadthroughthesemuskegs.SouthofNancyLakethecorridorandthetransportationcorridorsdiverge,andalthoughcoverbecomesmoresporadic,thelinewillnolongerb~visiblefromthetransportationroutes.ThetransmissionlinewillnotbevisiblefromtheNancyLakeRecreationArea.AstheAlaskaRailroadandthetransmissioncorridorapproachGoldCreek,thevalleybecomesmoreconfined,andscreeningbecomesmoredifficult.However,,tappearsthatthelinecanbeconcealedthroughmostofthisportion.!:;c.'"dUseandResources:FromPointMacKenzietoNancyLal,ethecon-idol'followsnoexistingcorridorfor32miles.NorthofNancyLocketoGoldCreekthecorridorparallelstheAlaskaRailroad,andtoTalkeetnatheAnchorage-FairbanksHighwayandMatanuskaElectricAssociationdistributionlines.Althoughagricultureinthisareaisvirtuallynon-existantbeyondoccasionalsubsistencegardens,thereispotentialinthebetterdrainedsoilstosupportfarming.ThecorridorwillencountersomeagriculturenearNancyLake,andagainabout25milesnorthnearthesettlementofMontana.Impactonagriculturewillbeverylow.GoodstandsofblackcottonwoodandbalsampoplarexistneartheTalkeetnaRiver,butthereisnoextensiveforestrytobeimpactedbythecorridor.Futureforestrymayutilizetheaccessroadbothforloggingandasafireroad,butthisimpactislowanddependsalsouponthelandownership.41 Impactonmineralresourcesislow;thecorridordoesnottraversesignificantareasofpotentialmetallicminerals,anddoesnotapproachanyexistingcoaloroildevelopmentsalthoughthepotentialforcoal,oilandgasexistsalongnearlytheentirelengthofthecorridor.Duetotheinefficiencyoflocaltapona345kvline,thelikelihoodofthedevelopmentoftheseresourcesduetotheproximityofatransmis-sionlineislow.Social:Fewtownsareencounteredbythecorridor.Wheneverpossible,thefinallocationwillcircumventcommunities.Theconstructionphasewilllastaboutthreeyears.Duringthattime,workonthetransmissionlinewillaffectthesecommunities.Thenumbersofworkersneededonatransmissionlinerelativetoapipelineislow.Workerswillbehousedincamps,orwillbebasedinAnchorageorFairbanks,bothofwhicharelargeenoughtoabsorbtheworkforce.Laborwillprobablyberecruitedfromthesecitiesorbroughtinbythecontractors.Littleornolaborforcewillbedr,·vnfromthesmallercommunitiesSlllceitisnotexpectedthattheirresidentsmighthavetheskillsandqualificationsfortransmissionlinework.Someeconomicimpactcanbeexpected,asflyingservices,motels,restaurants,andentertainmentsreceivebusiness,notonlyfromthetransmissionlineworkers,butfromrelatedpersonnel,also.Talkeetnaistheonlycommunity,exceptAnchorage,receivingtheseimpactsfTomcorridorSusitna-l.Itcanbee",.'pectedthatAnchoragecouldaeptthisimpactwithlittlestrain,buttheimpactmaybehighfor·f·allceetna.Theimpactsmaybeadverseinthatservicesmightbetemporarilymonopolizedbytheconstructionactivity,andgoodinthatitwouldbringconsiderablemoneytobusinessinthetown.ImpactsofPreferredCorridorNenana-lSoils:TheincidenceofpermafrostincreasesfromDevilCanyonnorthtoFairbanks;however,itisgenerallydiscontinuous,withafairlydeeptable.Impactsresultingfromthermaldegradationwillbelow,exceptforsoilsintheMoodyareawhichareice-rich.AsinSusitna-l,soilsvaryfrompoorlydrainedsoilsonlowlands,andbetterdrainedsoilsonslopes.Erosionpotentialforthemajorityofthecorridorislowtomediumsincethegreaterportionofthecorridorisonrelativelylevelland.TwosignificantexceptionsarethesectionsintheNenanaCanyonandthe"GoldstreamHills."TheNenanaCanyonareaposessevereerosionalproblemsduetothesteepslopesencountered.Discontinuouspermafrostisfound,whichpresentsahighpotentialfordegradation.42 Duetothephysicalandpoliticalrestraints,thecorridorwillhavetotraversemanyslopes.Soilsareoftenshallowontheseslopes;indeed,manyofthemaretalus.Foundationsmayhavetobeblastedintorock;constructionofanaccessroadwouldbeprohibitive,andforthisandotherreasonsanaccessroadwillnotbeusedonthisstretch.TheuppercanyonisconstrictedbetweenPanaramaMountainandtheNenanaRiver,andanextensive,unstabletalusslopeliesatthefootofPanoramaMountain.Inthelowercanyon,thin,unstablesoilblanketsthesteepslopetotheeastofthehighway.Wherethecorridortraversesslopessuchasthese,erosionwillbeaseriousproblem,especiallyonthinsoilsorunstablesoils.ThisimpactwillbeespeciallyobjectionablesinceerosionscarsmaybevisiblefromtheAnchorage-FairbanksHighwayandMt.McKinleyNationalPark.TheNenanaCanyonareaisalsointhevicinityofseverallargefaults.TheDenaliFaultcrossesthecorridorjustnorthofCantwell,andanotheractivefaultisencounterednearHe.,ly,northofthelowercanyon.Thisfactorwillaffectlocationofthetransmissionlineonunstableslopes.ThesoilintheGoldstreamHillscontainslensesoffinegrainmaterialwhich,combinedwiththeslopesencounteredbythecorridor,posesapotentialerosionproblem.Fortunately,rainfallisscantinthisarea.ThelowlyingareasintheGoldstreamHillshaveashallowpermafrosttable;soavoidingthepotentiallyerodablefinegrainsoilsbylocatingt1"transmissionlinelowwillpresentaproblemwithfrozensoils.,dmuskegs.ThecorridorwillcrossPortageCreek,theWestandMiddleForksoftheChulitnaRiver,theJackRiver,theNenanaRiver,YanertFork,HealyandLigniteCreeks,andtheTananaRiver.WiththeexceptionoftheNenanaandTananaRiversandYanertFork,theseareclearwaterstreams.Fordingsandcrossingswhichdisturbthebottomwillaffectwaterquality,aswillrun-offintothesestreamsfromadisturbedclearing.Vegetation:Upto1,440acreswillneedclearingalongthiscorridor.Actualacreageofclearingwillprobablybemuchlesssincethisfigureassumesclearingtothefullwidthoftheright-of-way.Inmanyareas,onlytheareasaroundthetowerbaseswillrequireclearing,particu-larlyinthelowlandspruce-hardwoodandmuskeg-bogecosystems.Theheaviestclearingswillbenecessaryinthebottomlandspruce-poplaranduplandspruce-hardwoodecosystemsalongthelowerNenanaRiverandtheTananafloodplain.Alongthegreaterpartofthecorridor,theaccessroadcanbeincorporatedintotheclearingduetolevelterrain.FromDevilCanyontoHealy,therewillbenoaccessroad.43 Themostimmediateeffectofclearingwillbethedestructionoftheclearedvegetation.Thetimberclearedfromthebottomlandspruce-poplarwillbesold,ifmerchantable.Otherwise.downedtimberandslashmustbedisposedofbyopenburningwhenpossibletopreventinfestationofstandingstockswithsprucebeetleCDendroctonusrufipennis)andtheaccumulationoffuelforwildfire.Somedisruptionofthesoilfromclearingistobeexpected;increasederosionbecauseofthis,andenhancedbythelackofcover,willresult.Ifvegetationiscleareduptoriverbanksonstreamcrossings,thismayresultinadditionalsiltation.Clearingwillentailhabitatmodifi-cation,tobediscussedunder"Wildlife."Regrowthratesalongthiscorridorareslowenoughtonotrequireaprogramofvegationsuppressionotherthanoccasionalcuttingduringroutineinspectionandmaintenancepatrols.Wildlife:Therewillbelossofindividualsmalleranimals,anddisplace-mentofothers;however,thisisatemporarysetback.Highreproductiveratesofsmallermammalsandre-invasionwillalleviatethisimpact.Apermanenthabitatmodificationwillresultfromtheclearingandmaintenance;acorridorofbrushwillbemaintainedthroughotherwiseforestedland.Animalsd0pendentuponclimaxforest,suchassquirrels,willsuffersomehabitatloss.Animalsdependentuponbrushandforbsforbrowsewillgain.Apartfromlocalconcentrations,theonlymajormooseconcentrationd"ongthiscorridoroccursfromHealytotheTananaRiveralongtheNenanaRiver.Aftertheconstructionphase,moosewillbenefitfromthe"edge"environ-ment,offeringincreasedbrowseimmediatelyadjacenttoforest,whichprOvidescover.Dependinguponthefinallocation,theaccessroadmayresultinadditionalhuntingpressureuponmooseinthisarea.Thiswillalsodependuponthechanceofmorehuntersintheareathanpresentlysinceifthenumberofhuntersremainsthesame,thereisnoreasontosuspectthatincreasedaccesswillresultinbetterhuntingsuccess.InpassingthroughthelowerNenanaCanyon,theNenana-lcorridortraversesDallsheephabitat.However,sincethesheeptendtoinhabitareashigherthananyfeasiblelinelocation,andsincenoaccessroadwillbeusedinthisarea,impactonDallsheepwillbelowtonone.44 Recreation:TheNenana-lcorridorwillparalleleightmilesofthenortheastborderofDenaliStatePark,butwillbeseparatedfromtheboundarybyIndianRiver,theAlaskaRailroad,andatleastonemileofbuffer.Furthernorth,itparallelstheeastborderofMt.McKinleyNationalParkfor30miles,beingseparatedbytheNenanaRivel',theAnchorage-FairbanksHighway,andtheAlaskaRailroad.Atnopointwillthecorl'idorcrosslandsproposedasadditionstotheMt.McKinleyNationalPark.Theaccessroadwillopenupnoextensivepreviouslyinaccessibleareassinceitwillparallelexistingtransportationafewmilesdistant;norecognizedwildernessareasareinfringed.Useoftheaccessroadbythepublicwillbedeterminedbytherelevantland-managingagency.IfthefinalroutelocationcrOSsestheClearMEWS,restrictionsmaybeplaceduponpublicuseofthisportionoftheaccessroad.CulturalResources:TheNationalRegisterofHistoricandArcheologicalSiteslistsonlyonesiteapproachebytheNenana-lcorridor,theDryCreekarcheologicalsite.ThisliestothewestofHealy,theNenanaRiver,andtheexistingtransportationcorridors.SincethecorridorrunsalongtheeastbankoftheNenana,therewillbenoimpactonthissite.IfthefinalroutesurveydisclosesanunsuspectedarcheologicalorhistoricalsitewithpotentialforinclusionintheNationalRegister,minorrouterelocations,orcarefultowerlocation,willprotecttheses,s.Inadvertantalterationofasitewillreduceordestroyits1istoricalvalue.ScenicResources:ThecorridorpassesthroughanarearecognizedasbeingofgoodtohighscenicqualityfromDevilCanyontoHealy.ThepossibilityofscreeningthroughoutthisareavariesfrommoderateinthesouthernportionaroundChulitna,tominimalintheBroadPassandtheupperandlowercanyonsoftheNenanaRiver.Scenicqualitywillbeimpacted,theimpactbeingafunctionofexistingscenicqualityandtheopportunityforscreening.ImpactintheNenanaCanyonwillbehigh;impactonBroadPasswillbemoderatetohigh;impactelsewherewillbemoderate.Twofavorablefactorsmitigatetheimpactsomewhat:1)ThecorridorisnotvisuallyintactastheAlaskaRailroadandtheAnchorage-FairbanksHighwayhavealreadyreducedscenicqualitysomewhat.2)Themajorviewssouthofthecanyonsaretothewest,towardtheMt.McKinleymassif,whereasthecorridorliestotheeastofthetransportationroutes,themostlikelyviewpoints.(SeeMitigatingMeasures.)45 LandUseandResources:TheNenana-lcorridorfollowsexistingcorridorsforitsentirelength.For10milesitfollowstheAlaskaRailroadfromGoldCreek.FromnorthofChulitnatoEsteritfollowsacombinedRailroad/Highwaycorridor.FromHealynorthitalsoparallelstheGoldenValleyElectricAssociation138kvtransmissionline.AlthoughthepotentialforagricultureexistsalongthiscorridorintheTananaValleyportion,itexistsintheformofhomegardensandgrazingifatall.Impactonexistingandpotentialagricultureislowtonone.Someforestryexistsinthebottomlandspruce-poplarforestsalongthelowerNenanaRiverandtheTananaRiver.Possiblesalesofmerchant-abletimberfTomtheclearinginthisareawillbringshort-livedbusinesstothetownofNenana,butthisimpactwillbelow.Useoftheaccessroadasaloggingroadandfirebreakmayoccur,butthisusewillnotsignificantlyaffectlogginginl',isarea.Althoughthecorridorapproachesandcrossesseveralmineralizedareasandfossilfueldeposits,Itwillnotmakepowerdirectlyavailablefordevelopmentexcepttbl'oughdistributionsystemsoftheexistingelectricutilities.Theaccessroadmaybeusedasaprospectingroad,butwillnotserveforhee,vieruse.Thevalueofthemineralsandfuelissuchthatifaprofitableareaweretobedeveloped,itwouldbefeasibletorelocatesmallsectionsofthetransmissionline.OntLwhole,impactonexistingandpotentialmineralandfuelextraction'clow.SlightlymorethanhalfofthelengthofthiscorridorpassesthroughtheMt.McKinleyCooperativePlanningandManagementZoneofEcologicalConcern.ThisisastudyareaofajointState-FederalPlanningandManagementCommitteeresponsibleforlanduseplanningintheareaperipheraltotheMt.McKinleyNationalPark.Social:Thesetownswillbeaffectedbythecorridor:Cantwell,Healy,Nenana,andFairbanks.Cantwellisasmallcommunitywithnoelectricutility,andfewservicesapartfromarailroadstationandafewrestaurant/motel/gasstations.IncomingmaterialmayarriveattheAlaskaRailroad;possiblecongestionofthestationmayoccur.Thisisaninsignificantimpact,however,andquitetemporary.ItispossiblethatCantwellwilltapdirectlyfromthe230kvtransmissionline.Electricalservicewilleitherbeviafuturedistributionlinesofoneoftheexistingutilitiesorbytappingfromanewsubstation.Thepresenceofanearbytransmission41, linewillundoubtedlyresultinincreasedpressurefromthecommunityforelectricalservice;althoughwhichofthetwomethodswillbedetermin-edbythecostandfeasibilityofboth.HealyissimilartoCantwell,exceptthatitisservedbytheGVEAsystem'sHealysteamplant.Nenanaisafairlyimportanttransportationnode,situatedatthecrossingoftheTananaRiver,anavigablewaterway,bytherailroadandhighwaycorridors.Situatedinabottomlandspruce-poplararea,ifthetimberfromalineclearingistobesold,thenthelogswillpassthroughNenana,offeringsomebusinessandjobs.ItisunlikelythatmuchlaborfortheactuallineconstructionwillbedrawnfromNenana.ThetownisalreadyservedbytheGVEAsystem.TheexistingHealy138kvlinepassesveryclosetothetown.ForashortstretchitusesshortertowersandspanstominimizehazardstoaircraftusingtheFAAstripsouthoftown.Thecorridorwillbefarenoughfromtheairstriptoreducethishazardtoaminimum,andanyspansdeemedhazardousbytheFAAwillbemarked.ImpactsofAlternativeSusitna-2AlternativecorridorSusitna-2duplicatesSusitna-lfromPointMacKenzietoTalkeetna.Impactsareidenticalforthissegment,andarediscussedunderimpactsofpreferredcorridorSusitna-l.ImpactsdiscussedhereareforthesegmentfromTalkeetnatoGoldCreekviaTroublesomeCreek.Soils:Inthesouthernportionofthisalternativethereisahighpropor-tiC'"ofpoorlydrainedsoilswhichcanbeexpectedtopresentproblemsfortowerfootingsandaccessroads.Theseverityoftheproblemwill0ependuponthevulnerabilityofthesoiltofrostheavingandtheabilityofthefinallinesurveytoavoidareasofpoorsoils.IntheuplandareasaroundTroublesomeCreek,gravellysoilswillpresenterosionalproblems,particularlysincesteeperslopesareencountered.Frostheavingshouldbelessofaconcern,andmainten-anceoffootingswillbeless.Therewillbelittleornoproblemwiththermaldisruptionofpermafrostasthereisonlydiscontinuous,deeplyburiedpermafrostalongthisalternative.However,finallinesurveycanlocateandavoidanyhighriskareas.Thermaldisruption,particularlyintheuplandareas,couldleadtogulleyingandotherformsoferosion.CrossingsoftheTalkeetnaandSusitnaRivers,parallelingofWhiskersCreek,andapossiblecrossingofTroublesomeCreekarenecessary.FordingoftheTalkeetnaandSusitnaRiversisunlikely.Inanyevent,theriversarebothalreadysiltladenriversandwillbelittleaffected47 byadditionalsilt.SiltwillnegativelyimpactfishhabitatintheWhiskersandTroublesomeCreeks,bothofwhichareclearwaterstreams.Vegetation:TheamountofclearingfortheSusitna-2alternativeisupto2,375acres,67acresmorethanthatforSusitna-1,ifthelineistobe345kv.A230kvlinewouldrequireupto2,121acres,61morethanasimilarlinealongSusitna-l.Theactualacresofclearingwillprobablybelessthanthesefiguressincesomestretchesmayonlyrequireclearingfortheaccessroadandthetowerbases.Inthesouthernportiontheterrainisflatenoughsothattheclearingwillincludetheaccessroad;inthesteeperterraintheaccessroadmayhavetodeviatefromtheright-of-waytomaintaingrade,andthiswillrequireadditionalclearing.Theimmediateeffectofthisclearingwillbethedestructionofthevege-tation.Themuchmoresignificantimpactwillbeuponerosionand",iJdlifehabitats.Inhillyterrain,mechanicalclearingmethodssuchasbulldozingwillcauseconsiderabledisruptionofthesoil,andsubsequenterosionandstreamsiltation.Theuseofbrushbladeswillreducethiseffect.Onsteepslopeshandclearingwillmitigatetheotherwiseheavyerosionpotentiallikelywithmechanicalclearing.Toreduceavailablefuelforforestfires,andtoreducepotentialinfestationofhealthytreesbysprucebeetles(Dendroctonusrufipennis)andipsbeetles,slashmustbedisposedof.Thiscanbeeitherbysale0,Llerchantabletimberorbyburning.Althoughburningwillreduce.irqualitytemporarily,itismoreeconomicalandlessdamagingthanthealternatives.(SeeMitigatingMeasures.)Regrowthratesalongthiscorridorarefastenough,particularlyinthesouthernportion,towarrantperiodicsuppressionoftallgrowingtreeswhichposeahazardtothetransmissionline.Thepreferredmethodalongthiscorridorismanualapplicationofasuitableherbicide.Theamountofclearingtobemaintained,themodestregrowthrates,andhighcostoflabormakethisalternativepreferableinthiscorridoroveraerialapplicationofherbicidesontheonehand,orhandcuttingofindividualtreesontheother.Ifproperapplicationtechniquesareadheredto(seeMitigatingMeasures),therewillbenootherimpactsotherthanthemaintenanceofasub-climaxvegetation.Accidentaloversprayingorwinddrift,orimproperdilution,resultinginunneces-sarydestructionofvegetationandsprayingofwaterbodiesresultinginhabitatdestructionforaquaticlifeisnotlikelytooccurwithmanualapplication.Sectionsneedingvegetationsuppressionoccurinthebottomlandspruce-poplar,lowlandspruce-hardwood,anduplandspruce-hardwoodforest,48 particularlyinthebottomlandspruce-poplar.Muskeg-bogandmoisttundraareas,whichcompriseasignificantproportionoftheecosystemscrossedbythiscorridor,willneedlittleornoclearingandnovegetationsuppression.Lowlandspruce-hardwoodareaswillnotneedtobe",aintainedasoftenasbottomlandspruce-poplar.Wildlife:Alterationofvegetationpatternswillaffectwildlife.Thiscorridortraversesmanyareasofmooseconcentration,andmooseshouldbenefitfromtheintroductionofbrushresultingfromtheregrowthontheclearing.Sincetheclearingmustbemaintained,thisbrushareawilllastforthelifeoftheline.Mostbrushareasareintransition,changingfromthebrushphasetosomeotherphaseapproachingtheclimacticphase.Thebrushinatransmissionclearingcanbecountedasamorepermanentsourceofbrowse.Animalsdependentuponclimacticforest,suchassquirrels,willsufferlossanddisplacement.However,theirfasterreproductiverateswillallowtheirpopulationstnadaptrapidly.Mostanimalswillbenefitfromtheedgeenvironment,offeringbothforageandcoverfromtheadj:icentforestandbrush.Initially,animalmovementsmayoccuralongtheright-of-way,butasthebrushgrowsintoadensecover,thiswillbelimited.Inanyevent,thisimpactshouldbelowinthiscorridor.Constructionitselfwillaffectwildlife.LargermammalsmaytemporarilyIe.vetheareatoreturnaftertheconstructionactivity.Smalleranimalswillsufferlossofindividuals,butshouldrecuperaterapidlyonceconstructioniscompleted.Thedensityofforestinthiscorridorwillallowanimalstomoveonlyashortdistancetoavoidcontactwithconstruc-'donactivities.Vegetationsuppression,bywhatevermethod,willperiodicallyremovecoverfromalongtheright-of-way.However,duetothesurroundingcoveroftheunclearedforests,thisimpactwillbeinsignificant.Recreation:Thiscorridorpenetrates26milesoftheDenaliStatePark,corningwithin4milesoftheAnchorage-FairbanksHighwaynearthePark'ssouthernborder.ThisputsthecorridorwithineasywalkingdistanceofthehighwayforasignificantpartofiislengthwithinthePark.Thiswillaffectpresentandpotentialtrailsintersectingthecorridor.49 AccessibilitytotheParkwouldbeincreasedbythecreationofanaccessrouteparalleltothehighway;however,thehighwayandtheSusitnaRiverarenotseparatedmorethannineorlessthanfourandahalfmiles,sothecorridor,whichseparatesthetwo,willnotserviceaninaccessiblearea.HuntingispresentlyprohibitedinDenaliStateParksoanaccessroadwillhavenovalueashuntersIaccess.ImpactonrecreationwillbenegativesincetheentireareaoftheParktotheeastofthehighwaywillbelimitedforhikinganddaytrails.CulturalResources:TheNationalRegisterlistsnohistoricalorarcheo-logicalsitesalongthiscorridor.Ifthefinalroutesurveylocatesa.Tlarcheologicalsite,minorrelocationorcarefultowerlocationwillavoiddisruptionofthesite.Inadvertantdisruptionofanarcheologicalsitewillreduceordestroyitsarcheologicalvalue.ScenicResources:Thetransmissionlinecanbeeffectivelyhiddenfromthehighwayforitsentirelength;however,itsimpactisstillhighbecauseofconflictswiththe('istingandpotentialtrailsintheStatePark.Asignificantvalueofthesetrailsisaesthetic,andvisibilityofatransmissionlinefromaninterceptedoradjacenttrailwillseriouslydetractfromtheoriginalpurposeofthesetrails.LandUseandResources:Tl·"majorlanduseofthissegmentisscenicandrecreational.Impactsareasdescribedaboveunder"Recreation"andlIScenicResources.HTJ)"ewillbenosignificantimpactonforestryoragriculturebecauseoftheexclusivenatureoftheStateParklanduse.TherewillbenoJ.lnpactsonotherresourcesinthissegment.ImpactsofAlternativeSusitna-3Soils:Thesoilsencounteredalongthisalternativearebasicallywellsuitedtotheconstructionofanaccessroad.Thelowerosionpotential,absenceofsignificantpermafrost,andthegravellytextureindicatethateffectsoferosionandconsequentsiltationwillbelow.Dependinguponthefinalroutesurvey,severalsmallclearwatercreekswillbecrossed.Somesiltationwilloccurfromfordingofconstructionequipment.Thissiltationwillbeofatemporarynature,andoflowsignificancesincethisuplandareaisnotanimportantfishery.TheTalkeetnaRiverwillneedatleastonecrossing,butprobablywillnotbeforded.SincetheTalkeetnaRivercarriesaglacialsiltload,additionalsiltationwillnotbesignificant.50 Theuplandsoilsarequiteshallow;excavationoffootingsmayrequireblasting.Accessroadlocationmayhavetodeviatefromthetransmissionlineinordertokeepanacceptablegradewithoutextensiveexcavation.Vegetation:TheSusitna-3alternativefor345kvcouldrequireupto1,900acres,407acreslessthanthatforSusitna-l,For230kv,thisalternativewouldrequireupto1,696acres,364acreslessthanasimilarlinealongcorridorSusitna-l,ThemajorityofthisclearingwilloccurintheTalkeetnaRivervalley.LittleornoclearingwillberequiredintheuplandareastowardDevilCanyon.Theimmediateeffectofthisclearingwillbethedestructionofthevegetation.Themuchmoresignificantimpactwillbeuponerosionandwildlifehabitats.Inhillyterrainmechanicalclearingmethods,suchasbulldozing,willcauseconsiderabledisruptionofthesoilandsubse-quenterosionandstreamsiltation.Theuseofbrushbladeswillreducethiseffect.Onsteepslopes,handclearingwillmitigatetheotherwiseheavyerosionpotentiallikelywithmechanicalclearing.Toreduceavailablefuelforforestfiresandtoreducepotentialinfesta-tionofhealthytreesbysprucebeetles(Dendroctonusrufipennis)andipsbeetles,slashmustbedisposedof.Thiscanbeeitherbysaleofmerchantabletimberorbyburning.Althoughburningwillaffectairqualitytemporarily,itismoreeconomicalandlessdamagingthanthealternatives.(SeeMitigatingMeasures.)R.cTOWthratesalongthiscorridorarefastenough,particularlyinthesouthernportion,towarrantperiodicsuppressionoftallgrowing.,,eswhichposeahazardtothetransmissionline.Thepreferredmethodal0ngthiscorridorismanualapplicationofasuitableherbicide.Theamountofclearingtobemaintained,themodestregrowthrates,andhighcostoflabormakethisalternativepreferrableinthiscorridoroveraerialapplicationofherbicidesontheonehandorhandcuttingofindividualtreesontheother.Ifproperapplicationtechniquesareadheredto(seeMitigatingMeasures),therewillbenootherimpactsotherthanthemaintenanceofasub-climaxvegetation.Wildlife:Alterationofvegetationpatternswillaffectwildlife.ThiscorridortraversesmanyareasofmooseconcentrationintheTalkeetnaRivervalley,andmooseshouldbenefitfromtheintroductionofbrushresultingfromtheregrowthontheclearing.Sincetheclearingmustbemaintained,thisbrushareawilllastforthelifeoftheline.Most51 brushareasareintransition,changingfromthebrushphasetosomeotherphasenearertheclimacticphase.Thebrushinatransmissionclearingcanbecountedasamorepermanentsourceofbrowse.Animalsdependentuponclimacticforest,suchassquirrels,willsufferlossanddisplacement.However,theirfasterreproductiverateswillallowtheirpopulationstorecuperaterapidly.Mostanimalswillbenefitfromtheedgeenvironment,offeringbothforageandcoverfromtheadjacentforestandbrush.Initially,animalmovementsmayoccuralongtheright-of-way,butasthebrushgrowsintoadensecover,thiswillbelimited.Thisimpactshouldbelowinthiscorridor.Theremaybeapossibleimpactonthecaribouwinterrangereportedtoexistin intheuplandareasalongthisalternative.Summerconstruc-tionwillreducecontactsofcaribouandtheconstructionactivity.J:;",'esstartedbyconstructionmaydestroypotentialwinterbrowse.Thedegreeofthisimpactdependsupontheareaburnedandtheseasonoftheburning.Largermammalsmaytemporarilyleavetheareatoreturnaftertheconstructionactivity.Smalleranimalswillsufferlossofindividuals,butshouldrecuperaterapidlyonceconstructioniscompleted.ThedensityofforestinthiscorridorwillallowanimalstomoveonlyasJ'~rtdistancetoavoidcontactwithconstructionactivities..egetationsuppression,bywhatevermethod,willperiodicallyremovecoverfromalongtheright-of-way.However,duetothesurroundingcoveroftheunclearedforests,thisimpactwillbeinsignificant.Herbicideswillnotdirectlyaffectanimalsinthedilutionsusedformanualspraying;herbicidesusedonright-of-waymaintenancearenon-cumulativeandarereadilyexcreted.Theoveralladverseimpactofherbicidesprayingwillbelow,asitwillbenecessaryonlyeveryfivetotenyears,whereastheavailabilityofforageprovidedisaspermanentasthetransmissionline.Recreation:Thiscorridorapproachesnorecognizedrecreationarea.SincetheentirelengthofthissegmentfromTalkeetnatoDevilCanyonparallelsnoexistingtransportationline,asizeableamountoflandisopeneduptoaccessbyfour-wheeldrivevehicles,dependentuponthepoliciesofthelandownersormanagingagency.Forrecreationrequiringvehicularaccess,thisincreasedaccesswillhaveabeneficialimpact.Forrecreationdependentuponprimitivevalues,increasedaccesswillhaveadetrimentalaspect.52 CulturalResources:Thereisnoknownimpactonculturalresourcesinthissegment.ScenicResources:Intermsofviewercontacts,thiscorridorwillhavealowimpactonscenicqualityduetoitsrelativeinaccessibility.How-ever,thiscorridorwillhaveahigherimpactupontheintactnessofthisareathanthecomparablesegmentsofSusitna-landSusitna-2.Thehighprimitivevaluesandmediumtohighscenicvalueofthiscorridor,coupledwithrelativelyhighvisibilityofatransmissionlineintheuplandarea,willresultinahighimpactonscenicquality,dis-regardingthefactorofviewercontacts.LandUseandResources:NoimpactonagricultureisanticipatedalongthiscorridorfromTalkeetnatoDevilCanyon.AnaccessroadwillnotenhanceforestryintheTalkeetnaRivervalleysinceitwouldbeunsuit-ableforaloggingroadunlessitwereoverbuilt,andsincetheaccessroadwouldrunveryclosetothet1'~nsmissionlineitself.Impactsonnuneralresourceswillalsobelow;notenoughpotentialexistsalongthecorridortobeinfluencedbytheincreasedaccess.Social:Nocommunitiesareencounteredalongthiscorridor;sothereisnoimpact.ImpactsofAlternativeSusitna-4Sc~'~ForsoilsintheportionofthiscorridorthatfollowstheTalkeetnaPiverandPrairieCreek,impactsfromerosion,siltation,andpermafrost,-,,,,gradationarelow.CrossingsoftheTalkeetnaRiverandIronCreekWIllbenecessary.Bothofthesestreamsaresedimentladen;soaddi-tionalsiltationwillhavelittleeffect.Thesoilsontheuplandportionofthiscorridoraremoresusceptibletoerosion,althoughtheslopesareshallower.Animproperlyconstructedaccessroadwillcauseerosion.Veryfewcreeksarecrossed.Siltationwouldbeaveryminorproblem.Somepermafrostassociatedwithpoorlydrained,peatysoilsmaypresentproblems,notonlyofpermafrostdegradation,butoffrost-heaving.However,finallinesurveyshouldreducethispotentialimpact.Unavoidablestretchesofpoorlydrainedsoilsmayberuttedandscarredbyvehicletracksunlesstheaccessroadishardenedwithagravelbed.Vegetation:Fora345kvlinethiscorridorcouldrequireupto2,257acresofclearing,50acreslessthanSusitna-l.Fora230kvdesignitwouldrequireupto2,105acres,45acreslessthanasimilarlineon53 Susitna-l.Actualacreagesofclearingwillprobablybelessthanthesefiguressincetheentireright-of-waywillinmostcasesnotbecleared,andalongsomestretchesonlytheaccessroadandtowerbasesneedtobecleared.Theimmediateeffectofthisclearingwillbethedestructionofthevege-tation.Themuchmoresignificantimpactwillbeuponerosionandwild-lifehabitats.Inhillyterrain,mechanicalclearingmethodssuchasbulldozingwillcauseconsiderabledisruptionofthesoilandsubsequenterosionandstreamsiltation.Theuseofbrushbladeswillreducethiseffect.Onsteepslopes,handclearingwillmitigatetheotherwiseheavyerosionpotentiallikelywithmechanicalclearing.Toreduceavailablefuelforforestfiresandtoreducepotentialinfesta-tionofhealthytreesbysprucebeetles(Dendroctonusrufipennis)andipsbeetles,slashmustbedisposedof.Thiscanbeeitherbysaleofmerchantabletimberorbyburning.Althoughburningwillaffectairqualitytemporarily,itismoreeconomicalandlessdamagingthanthealternatives.(SeeMitigatingMeasures.)RegrowthratesalongtheTalkeetnaRivervalleyarehighenoughsothatperiodicsuppressionoftallgrowingtreeswithintheclearingisrequired.Themethodtobeusedwillb"manuallyappliedherbicide,appliedtotargettreesduringreguhrmaintenancepatrols.Ifproperlyapplied,therewillbenocontaminationofwaterbodiesordestructionofnon-targetvegetation.Themostimportantimpactofthisprogramwillbethemainte-nceofsub-climaxbrushwithinforestedareas..\:'il1dlife:Alterationofvegetationpatternswillaffectwildlife.ThiscorridortraversesanareaofmooseconcentrationintheTalkeetnaValley,andmooseshouldbenefitfromtheintroductionofbrushresult-ingfromtheregrowthontheclearing.Sincetheclearingmustbemaintained,thisbrushareawilllastforthelifeoftheline.Mostbrushareasareintransition,changingfromthebrushphasetosomeotherphasenearertheclimacticphase.Thebrushinatransmissionclearingcanbecountedasamorepermanentsourceofbrowse.Animalsdependentuponclimacticforest,suchassquirrels,willsufferlossanddisplacement.However,theirfasterreproductiverateswillallowtheirpopulationstoadaptrapidly.Mostanimalswillbenefitfromtheedgeenvironment,offeringbothforageandcoverfromtheadjacentforestandbrush.Initially,animalmovementsmayoccuralongtheright-of-way,butasthebrushgrowsintoadensecover,thiswillbelimited.Inanyevent,thisimpactshouldbelowinthiscorridor.54 Constructionitselfwillaffectwildlife.Largermammalsmaytemporarilyleavetheareatoreturnaftertheconstructionactivity.Smalleranimalswillsufferlossofindividuals,butshouldrecuperaterapidlyoncecon-structioniscompleted.Thedensityofforestinthiscorridorwillallowanimalstomoveonlyashortdistancetoavoidcontactwithconstructionactivities.Vegetationsuppression,bywhatevermethod,willperiodicallyremovecoverfromalongtheright-of-way.However,duetothesurroundingcoveroftheunclearedforests,thisimpactwillbeinsignificant.Herbi-cidesappliedasoutlinedunder"Vegetation,"willproducefeweffectsuponanimals.Sincetheherbicidesareappliedonlytotargetvegeta-tion,theprobabilityofingestionisreducedtoaminimum.Herbicidesarenottoxictoanimalsintheconcentrationsnormallyused,andarenotcumulativeineffect..:3ecreation:Althoughthiscorrido.'doesnotapproachanyStateorFederalrecreationareasorparks,itwillaffecttherecreationaluseoftheuplandareanearStephenLake.Readilyaccessiblebyfloatplane,thisareaispopularwithsportsmenandvacationers.ThelakeshavemanycabinsalongtheirRhores,Theaccessroadwouldprovideanothermeansofaccessforthisare?"whichwouldtendtoincreasetherecrea-tionaluse,andatthesarr,etime,thetransmissionlinewouldbevisibleformostofitslengthovertheuplandarea.Ifoneoftheperceivedvaluesofthisareaisitsrelativeinaccessibility,thenincreasedaccess,": avisibletransmissionlinewouldhaveahighlydetrimentalimpact..,creasedaccessibilitytootherareastraversedbythecorridorwouldbebeneficialtorecreationalusedependentuponeasyaccess.CulturalResources:Ifthefinalsurveydisclosesanunsuspectedarcheologicalsitealongtheright-of-way,thelocationofthelineortowerswillbealteredtoavoiddamagetosuchsites.Inadvertentdamagetoanarcheologicalsitewillreduceitshistoricalvalue.Atthesametime,discoveryofanarcheologicalsiteduringsurveyorconstructionwillbeabeneficialaspect.ScenicResources:Intermsofviewercontacts,impactofatransmissionlinealongtheTalkeetnaRivervalleywillbelow.Alongtheuplandareaitwillbehigh.Thisareaisaheavilyusedrecreationarea,sparselyforested,andofmoderatetohighscenicquality.Thus,theconstructionofatransmissionlineandtheinherentvisibilityofsuchalinewouldresultinahighimpact.55 LandUseandResources:Therewillbesignificantimpacts,bothbene-ficialanddetrimental,onthepredominantlanduse,recreation.Theseimpactsarediscussedunderthe"Recreationllsectionabove.Therewillbenoimpactonagriculture,forestry,andmineralresources.Social:Therewillbenosocialimpactsfromthiscorridor.ImpactsofAlternativeNenana-2Soils:Impactsonsoilsalongthiscorridorwillbeidenticaltothoseout-linedinNenana-luptoCantwell.Thegenerallyflat,gravellysoilfromCantwelltoWellsCreekisvulnerabletowatererosion.ConstructionactivitiesmaycaUSegulleyinginthisarea.Thepeatypermafrostsoilsalsofoundinthisareawillpresentproblemsinconstructingtheaccessroad.Possibleruttingandscarringmayleadtodegradationoftheunder-lyingpermafrostandfurthererosion.FromWellsCreektotheupperWoodRiver,impactswillvarywiththetypeofsoilencountered,whichcanbelocalizedpoorlydrainedfrozensoil,thinsoilsandgravel,andbarebedrockandtalus.LocalpocketsofpoorlydrainedsoilsC2.Y,-beavoidedtoanextent.Unavoidableencounterswillresultindisturbanceoftnesoilandpossibleconsequentdisruptionofthepermafrost.Thinsoilsandgravelareverysusceptibletoerosion.particularlysincetheywillbefoundinconjunctionwithsteepslopes.Accessroadconstructionwillhaveadetrimentalaffectinboththesesoils.Noimpactonbarebedrockandtalusisanticipated;however,footingsforJIlerswillrequireblastingandconstructionofanaccessroadwillbeeytremelydifficult.Increasingamountsofpoorlydrained,frozen,peatysoilsencounteredfromalongthelowerWoodRivertotheTananaRiverwillcauseincreasingproblemswithaccessroadconstruction.footingstabilization,andruttingandscarringofthesoils.Unlesstheaccessroadisbeddedongravel,thereisastrongpotentialforpermafrostdegradationandconsequentgulley-ingandmaintenanceproblems.ImmediatelyadjacenttotheTananaRiver,stratifiedsoilspresentapotentialwatererosionproblem,yetareeasiertoconstructonthanthesurroundingpoorlydrainedpeats.Thesestrati-fiedmaterialsareoftenleveesofextinctorexistingchannels.Theyarelinear,butsinuous,andmayprovidenotonlythebestfoundationforaroad,butalsothehighestpointabovefloodwaters.56 Theimpactofsiltationonglacialriverswillbelow.SiltationimpactonclearwaterstreamswillbemediumforWellsCreek.LouisCreek.andDeanCreek.SiltationimpactsuponthenumerousclearwatertributariesoftheWoodRiverwillbelowsincetheywillbecrossedclosetotheirconfluenceswiththesiltladenWoodRiver.Vegetation:Thiscorridorcouldrequireupto1,500acresofclearing.60acresmorethanthatforNenana-l.Actualacreageclearedwillprobablybelessthanthisfiguresincetheentireright-of-wayneednotbecleared,andtheterrainrequiringtheheavierclearingisgenerallyflatenoughtoallowtheaccessroadtorunwithintheclearing.Theimmediateeffectofthisclearingwillbethedestructionofthevege-tation.Themuchmoresignificantimpactwillbeuponerosionandwildlifehabitats.Inhillyterrainmechanicalclearingmethodssuchasbulldozingwillcauseconsiderabledisruptionofthesoilandsubsequenterosionandstreamsiltation.TheuSeofbrushbladeswillreducethiseffect.Onsteepslopes,handdeeYingwillmitigatetheotherwiseheavyerosionpotentiallikelywithmechanicalclearing.Toreduceavailablefuelforfm'estfiresandtoreducepotentialinfesta-tionofhealthytreesbyspl'ucebeetles(Dendroctonusrufipennis)andipsbeetles,slashmustbedicposedof.Thiscanbeeitherbysaleofmerchantabletimberorbyburning.Althoughburningwillaffectairqualitytemporarily.itismoreeconomicalandlessdamagingthanthealternatives.(SeeMitigatingMeasures.)pxceptforthebottomlandspruce-poplarforestalongtheTananaRiver.regrowthratesarelowenoughsothatlittlevegetationsuppressionotherthanroutinetrimmingofdangertreesisnecessary.Moreexten-sivecuttingprogramsmaybenecessaryintheareaaroundtheTananaRiver.Inthemoisttundraandalpinetundraecosystems.disturbedareaswillbeveryslowtorecuperate.Revegetationwithappropriatespecieswillbenecessarytominimizesurfaceerosionandpermafrostdegradation.Properconstructionandaccessroaddesignwilllimitvegetationlosstotheareaoccupiedbytheroadbedandtowerbases.Noclearingisnecessaryintheseareas.Firescausedbyconstructionandmaintenancewillhavelittleimpact,providingtheyarediscoveredquicklyandstoppedwithoutexcessdisturbanceofthesoil.Thepresentpatternsofforestsarecausedbypreviousnaturallycausedfireswhichareanintegralfactorofthese57 ecosystems.Impactfromasmallnumberofadditionalfiresoflimitedareawillbelow.Wildlife:Thegreatestanticipatedimpactuponwildlifewillbethealtera-tionofvegetativepatterns.andthisimpactwillbeafunctionofthedegreeofclearing.Animalsdependentuponclimaxforestwillsufferlossofindividualsandlossofhabitat.Generally.thesearethesmallmammalssuchassquirrelandmarten.Moosewillbenefitfromthecreationofanareaofmaintainedbrowse.Sincetheclearingwillnotbeallowedtotalregrowth,thebrowsecreatedcanbeconsideredaspermanentastheline.Theconjunctionofforestandopenbrushcreatesafavorable"edge"environmentformostanimals.offeringforageontheclearingandcoverintheforest.Constructionactivitywilltemporarilyfrightenawaywildlife;however,thisisanextremelylocalandtemporaryimpact.Maintenancepatrolswillnotbefrequentenoughtokeepanimalsfromreturningtothecorridor.ImpactuponthecaribouwinteringrangesoneithersidesoftheAlaskaRangewillbelowifconstructivnisdoneinsummer.whichmaybepre-fenableinanycasebecauseofbetterworkingconditions.Dallsheephabitatwillbeimpactedinthattheywillbefrightenedawayfromcon-structionactivitymoresothancaribouandmOOSe.Again.thisimpactisofatemporarynature.Uncheckedfireineitherofthesehabitatswilladverselyimpactbothcaribouandsheep.Withcaribouparticularly.de'ructionoftheirkeywinterbrowse.lichen,mayhavelonglastingeffectsduetoslowregrowthrates.R"creation:ThiscorridordoesnottraverseanyFederalorStateparksorrecreationareas.Itdoes.however.brieflyapproachwithinfivemilesthesoutheastcornerofMcKinleyNationalPark.Exceptfor22milesalongtheDenaliHighway.thecorridorwillprovideaccesstoanareapreviouslyaccessibleonlybyairorfoot.Insomecases,accessispresentlypossiblewithall-terrainvehicles.Increasedaccesswillimpactgameanimalpopulationssomewhat;theactualimpactwilldependuponthedesirabilityoftheareaforhunting.andaccessandhuntingregulationsimposedbythelandmanagingagencies.CulturalResources:ThisalternativeapproachesnoNationalHistoricorArcheologicalSites.Ifthefinalsurveydisclosesanunsuspectedarcheologicalsitealongtheright-of-way.thelocationofthelineor58 towerswillbealteredtoavoiddamagetosuchsites.Inadvertentdamagetoanarcheologicalsitewillreduceitshistoricalvalue.Atthesametime,discoveryofanarcheologicalsiteduringsurveyorconstructionwillbeabeneficialaspect.ScenicResources:Thisalternativetraversesareasoflowtohighscenicquality.Intermsofviewercontacts,thiscorridorwillhavelittleimpactsinceitwillnotbevisiblefromtransportationroutesformostofitslength.Disregardingviewers,highvisualimpacttoscenicandwildernessqualityinthemountainousportionofthecorridorcanbeexpected.LandUseandResources:Therewillbenoimpactsonforestryandagriculturethroughoutthisalternative.Therewillbenoimpactsonmineralorfossilfuelresources.Apartfromobtainingeasements,noimpactisexpectedonexistinglanduse.ImpactsofAlternativeNenana-3Soils:ThemajorityofthesoilsontheportionofthisalternativewhichdiffersfromtheproposedNenana-1corridorarerocky,thinsoilsandbedrock,andassucharcwellsuitedgenerallyfortowerfoundations.Accessroadconstructionwillbehamperedbysteepslopes,bedrock,andtalusencounteredbythiscorridor.Erosionwillgenerallybelow,although<)•thinsoilsorunstableslopes,erosionwillbesevereunlesscorrectiveeasuresareemployed.Permafrostcanbeassumedtobecontinuous,butViillnotusuallybeofconcerntotowerlocationunlessthesoilisice-rich.Thisconditionisassumedtoberestrictedtovalleyfloors.Soilimpactsfortheremainderofthealternativearedescribedundersoilimpactsoftheproposedcorridor.Vegetation:TheNenana-3corridorcouldrequireupto1,318acresofclearing,121acreslessthanNenana-I.AlmostnoclearingisneededontheportionwhichdiffersfromtheNenana-lcorridorsincemostlyalpineandmoisttundraecosystemsareencounteredinthisportion.ImpactsresultingfromclearingwillbesimilartothosediscussedunderNenana-I.Alongthedifferingsegmentdestructionofvegetationwillbelimitedtothoseareasdirectlyoccupiedbytheroadbedandthetowerbases.Thiswillbeapermanentimpact,althoughsomerevegetationoftowerbasescanbeexpected.59 Destructionofthevegetativematintundraareaswillresultinlonglastingscarsunlesscorrectiveandpreventivemeasuresaretaken.Thisscarringcouldleadtosubsequentdegradationofice-richpermafrostanderosion.Firesresultingfromconstructionandoperation,unlesssuppressedquickly,willresultinextensivedestructionofvegetation.Theseecosystemsareadaptedtonaturalwildfires,andunlesstheoccurrenceofman-causedfiresisveryhigh,theyshouldrecuperateasquicklyastheywouldundernormalcircumstances.Wildlife:ImpactsonwildlifeforthosesegmentsofthisalternativecorridortoNenana-larediscussedunderimpactstowildlifeoftheproposedcorridor.Alongthedifferingsegment,therewillbelittleimpactfromhabitatmodificationduetoclearing.Increasedincidenceoffireresultingfromoperationorconstructionwi]]adverselyaffecthabitatforDallsheepandcaribou.Moosehabitatwillbeenhanced,uptoapoint,byfire.Constructionactivitymaycauseavoidanceofthecorridorbyanimals;however,thisisatemporaryimpact.Operationandmaintenancewillnotaffecttheanimals'occupationofthecorridor.IncreasedaccessaffordedbytheaccessroadmayincreasehuntingssureonDallsheep,caribou,andtoalesserdegreeonmOOSe,hedegreeofthisimpactisdependentuponthedesirabilityofthisvJrridorforhunting,andaccessandhuntingregulationsimposedbythelandmanagingagencies.Recreation:ThiscorridordoesnottraverseanyFederalorStateparksorrecreationareas.Itdoes,however,brieflyapproachwithin5milesthesoutheastcornerofMcKinleyNationalPark.Exceptfor22milesalongtheDenaliHighway,thecorridorwillprovideaccesstoanareapreviouslyaccessibleonlybyairorfoot.Insomecases,accessispresentlypossiblewithall-terrainvehicles.Increasedaccesswillimpactgameanimalpopulationssomewhat.Theactualimpactwilldependupondesirabilityoftheareaforhunting,andaccessandhuntingregulationsimposedbythelandmanagingagencies.CulturalResources:ThisalternativeapproachesnoNationalHistoricorArcheoh.,gicalSites.Ifthefinalsurveydisclosesanunsuspected60 archeologicalsitealongtheright-of-way,thelocationofthelineortowerswillbealteredtoavoiddamagetosuchsites.Inadvertentdamagetoanarcheologicalsitewillreduceitshistoricalvalue.Atthesametime,discoveryofanarcheologicalsiteduringsurveyorconstructionwillbeabeneficialaspect.ScenicResources:Thisalternativetraversesareasofmoderatetohighscenicquality.Intermsofviewercontacts,thiscorridorwillhavelittleimpactsinceitwillnotbevisiblefromtransportationroutesformostofitslength.Disregardingviewers,highvisualimpacttoscenicandwildernessqualityinthemountainousportionofthecorridorcanbeexpected.LandUseandResources:Therewillbenoimpactsonforestryandagriculturethroughoutthisalternative.Therewillbenoimpactsonmineralorfossilfuelresources.ImpactsofAlternativeNenana-4Soils:FromHealytoEster.thiscorridorduplicatesNenana-I,andimpactstosoilsareidenticaltothosediscussedunderimpactsofNenana-I.ThesoilsfromWatanaDamsitetoWellsCreekwillbeveryvulnerabletopermafrostdegradationandfrostheaving.ThevegetativematmustUCpreserved.andconstructionactivitymustbeplannedtominimize'isruptionofthesoil.Erosioncausedbypermafrostdegradationand1cessroadconstructionwillhaveadverseimpactsonwaterqualityintheclearwaterstreamsencountered.Fordingofstreamsinthissegment,giventhesensitivesoilconditions.couldresultinextensivebankerosion.Tominimizethisandtoensuretheintegrityofthetransmissionline,thecorridorwillavoidrivercrossingswhenpossible.FromWellsCreektoHealyviaNenana-4,thesoilsarerocky.thinsoilsandbedrock,andassucharewellsuitedgenerallyfortowerfoundations.Accessroadconstructionwillbehamperedbysteepslopes,bedrock.andtalusencounteredbythiscorridor.Erosionwillgenerallybelow,althoughonthinsoilsorunstableslopes,erosionwillbesevereunlesscorrectivemeasuresareemployed.Permafrostcanbeassumedtobecontinuous.butwillnotusuallybeofconcerntotowerlocationunlessthesoilisice-rich.Tbisconditionisassumedtoberestrictedtovalleyfloors.61 Vegetation:TheNenana-4alternativecouldrequireupto1,182acresofclearing,257acreslessthanNenana-I.Actualacresclearedwillprobablybelessthanthissincetheentireright-of-wayneednotbecleared.ImpactsonvegetationfromHealytoEsterareidenticaltothosediscussedforthatsegmentunderimpactsofNenana-I.AlmostnoclearingisneededontheportionwhichdiffersfromtheNenana-1corridorsincemostlyalpineandmoisttundraecosystemsareencounteredinthisportion.Impactsresultingfromclearingwillbesimilartothosedis-cussedunderNenana-I.Alongthedifferingsegment,destructionofvegetationwillbelimitedtothoseareasdirectlyoccupiedbytheroadbedandthetowerbases.Thiswillbeapermanentimpact,althoughsomerevegetationoftowerbasescanbeexpected.D"structionofthevegetativematintundraareaswillresultinlonglastingscarsunlesscorrectiveandpreventivemeasuresaretaken.Thisscarringcouldleadtosubsequentdegradationofice-richpermafrostanderosion.Firesresultingfromconsi:l'uctionandoperation,unlesssuppressedquickly,willresultinextendivedestructionofvegetation.Theseeco-systemsareadaptedtonaturalwildfires,andunlesstheoccurrencofman-causedfiresisveryhigh,theyshouldrecuperateasquicklyastheywenldundernormalcircumstances."dlife:Impactsonwildlifeforthosesegmentsofthisalternativecorridorto'lenana-1arediscussedunderimpactstowildlifeoftheproposedcorridor.Alongthedifferingsegmenttherewillbelittleimpactfromhabitatmodi-ficationduetoclearing.IncreasedincidenceoffireresultingfromoperationorconstructionwilladverselyaffecthabitatforDallsheepandcaribou.Moosehabitatwillbeenhanced,uptoapoint,byfire.Constructionactivitymaycauseavoidanceofthecorridorbyanimals;however,thisisatemporaryimpact.OperationandmaintenancewillnotaffecttheanimalsIoccupationofthecorridor.IncreasedaccessaffordedbytheserviceroadmayincreasehuntingpressureonDallsheep,caribou,andtoalesserdegreeonmoose.The62 degreeofthisimpactisdependentuponthedesirabilityofthiscorridorforhunting,andaccessandhuntingregulationsimposedbythelandmanagingagencies.Recreation:ThiscorridordoesnottraverseanyFederalorStateparksorrecreationareas.Thecorridorwillprovideaccesstoanareapre-viouslyaccessibleonlybyairorfoot.Insomecases,accessispresentlypossiblewithall-terrainvehicles.Increasedaccesswillimpactgameanimalpopulationssomewhat.Theactualimpactwilldependuponthedesirabilityoftheareaforhunting,andaccessandhuntingregulationsimposedbythelandmanagingagencies.CulturalResources:ThisalternativeapproachesnoNationalHistoricorArcheologicalSites.Ifthefinalsurveydisclosesanunsuspectedarcheologicalsitealongtheright-of-way,thelocationofthelineortowerswillbealteredtoavoiddamagetosuchsites.InadvertentdamagetoanarcheologicalsitewillreducE''tshistoricalvalue.Atthesametime,discoveryofanarcheologicalsiteduringsurveyorconstructionwillbeabeneficialaspect.ScenicResources:ThisaHernativetraversesareasoflowtohighscenicquality.Intermsofviewerc',ntacts,thiscorridorwillhavelittleimpactsinceitwillnotbevisiblefromtransportationroutesformostofitslength.Disregardingviewers,highvisualimpacttoscenicandwildernessqualityinthemountainousportionofthecorridorcanbeexpected.1"ndUseandResources:Therewillbenoimpactsonforestryand",gl'iculturethroughoutthisalternative.Therewillbenoimpactsonmineralorfossilfuelresources.ImpactsofAlternativeNenana-5Soils:ThesoilsfromWatanaDamsitetoWellsCreekwillbeveryvulner-abletopermafrostdegradationandfrostheaving.Thevegetativematmustbepreserved,andconstructionactivitymustbeplannedtomini-mizedisruptionofthesoil.Erosioncausedbypermafrostdegradationandaccessroadconstructionwillhaveadverseimpactsonwaterqualityintheclearwaterstreamsencountered.Fordingofstreamsinthissegment,giventhesensitivesoilconditions,couldresultinextensivebankerosion.Tominimizethisandtoensuretheintegrityofthetransmissionline,thecorridorwillavoidrivercrossingswhenpossible.63 FromWellsCreektoupperWoodRiverthesoilsarerocky,thinsoilsandbedrock,andassucharewellsuitedgenerallyfortowerfoundations.Accessroadconstructionwillbehamperedbysteepslopes,bedrock,andtalusencounteredbythiscorridor.Erosionwillgenerallybelow,althoughonthinsoilsorunstableslopeserosionwillbesevereunlesscorrectivemeasuresareemployed.Permafrostcanbeassumedtobecontinuous,butwillnotusuallybeofconcerntotowerlocationunlessthesoilisice-rich.Thisconditionisassumedtoberestrictedtovalleyfloors.TheWoodRivervalleyandTananaRivervalleypresentproblemswithlocatingwelldrainedsoils.Largeareasofpoorlydrainedpeatswithcontinuousshallowpermafrostwillresultinpotentialsevereimpactssuchaspermafrostdegradation,ruttingandscarringofthesurface,bankerosionwhereclearwaterstreamsareforded,anderosioncausedbyaccessroadconstruction.Thenecessaryclearingwillalsogreatlyaddtoerosionandsiltation.Preventiveandcorrectivemeasureswillneedtobeusedtominimizetheseimpa('s.Vegetation:Thiscorridorwillrequireupto1,369acresofclearing,74acreslessthanNenana-I.Actualacresclearedwillprobablybelessthanthisfiguresincetheentireright-of-wayneednotbecleared.Themajorityoftheclearing",.·i11bealongtheTananaRivervalleyandlowerWoodRiverinthebottomlandspruce-poplaranduplandspruce-hardwoodecosystems.Alongthegreaterpartofthecorridortheaccessroadcanbeincorporatedintotheclearingduetolevelterrain.'T'lemostimmediateeffectofclearingwillbethedestructionofthedearedvegetation.Downedtimberandslashmustbedisposedofbyopenburningwhenpossibletopreventinfestationofstandingstockswithsprucebeetle(Dendroctonusrufipennis)andtheaccumulationoffuelforwildfire.Destructionofthevegetativematintundraareaswillresultinlonglastingscarsunlesscorrectiveandpreventivemeasuresaretaken.Thisscarringcouldleadtosubsequentdegradationofice-richperma-frostanderosion.Firesresultingfromconstructionandoperation,unlesssuppressedquickly,willresultinextensivedestructionofvegetation.Theseeco-systemsareadaptedtonaturalwildfires,andunlesstheoccurrenceofman-causedfiresisveryhigh,theyshouldrecuperateasquicklyastheywouldundernormalcircumstances.64 Somedisruptionofthesoilfromclearingistobeexpected.Increasederosionbecauseofthis,andenhancedbythelackofcover,willresult.Ifvegetationiscleareduptoriverbanksonstreamcrossings,thismayresultinadditionalsiltation.Wildlife:Therewillbelossofindividualsmalleranimalsanddisplace-mentofothers;however,thisisatemporarysetback.Highreproductiveratesofsmallmammalsandre-invasionwillamendthisimpact.Apermanenthabitatmodificationwillresultfromtheclearingandmainten-ance.Acorridorofbrushwillbemaintainedthroughotherwiseforestedland.Animalsdependentuponclimaxforest,suchassquirrels,willsuffersomehabitatloss.Animalsdependentuponbrushandforbsforbrowsewillgain.ThelargeconcentrationofmoosealongthelowerWoodRiverandtheTananaRiverwillbenefitfromiheregrowthofbrushintoclearedareas.L.,11sheepandcaribouinthemountainousareaswillsuffersomelossofforagetotheroadbedandtowerbases.Excessivefirewilladverselyaffecttheforagefortheselasttwogameanimalssincetheyaredependentuponclimaxvegetationwhicnhasaslowregrowthrate.Moosewillbenefitfromfires,uptoapoint.Excessivefiresmaytriggererosionwhichwoulddegrade,rath"rthanenhance,browseformoose.Constructionactivitymaycauseavoidanceofthecorridorbyanimals;h"'''ever,thisisatemporaryimpact.Operationandmaintenancewill.,>[affecttheanimals'occupationofthecorridor.ILcreasedaccessaffordedbytheserviceroadmayincreasehuntingpressureonDallsheep,caribou,andmoose.Thedegreeofthisimpactisdependentuponthedesirabilityofthiscorridorforhunting,andaccessandhuntingregulationsimposedbythelandmanagingagencies.Recreation:ThiscorridordoesnottraverseanyFederalorStateparksorrecreationareas.Thecorridorwillprovideaccesstoanareapre-viouslyaccessibleonlybyairorfoot.Insomecases,accessispresentlypossiblewithall-terrainvehicles.Increasedaccesswillimpactgameanimalpopulationssomewhat.Theactualimpactwilldependuponthedesirabilityoftheareaforhunting,andaccessandhuntingregulationsimposedbythelandmanagingagencies.CulturalResources:ThisalternativeapproachesnoNationalHistoricorArcheologicalsites.Ifthefinalsurveydisclosesanunsuspected65 archeologicalsitealongtheright-of-way,thelocationofthelineortowerswillbealteredtoavoiddamagetosuchsites.Inadvertentdamagetoanarcheologicalsitewillreduceitshistoricalvalue.Atthesametime,discoveryofanarcheologicalsiteduringsurveyorconstructionwillbeabeneficialaspect.ScenicResources:Thisalternativetraversesareasoflowtohighscenicquality.Intermsofviewercontacts,thiscorridorwillhavelittleimpactsinceitwillnotbevisiblefromtransportationroutesformostofitslength.Disregardingviewers,highvisualimpacttoscenicandwilder-nessqualityinthemountainousportionofthecorridorcanbeexpected.LandUseandResources:Therewillbenoimpactsonforestryandagriculturethroughoutthisalternative.Therewillbenoimpactsonmineralorfossilfuelresources.ImpactsofAlternativeMatanuska-lSoils:FromDevilCanyontoVeeDamsite,someproblemsrelatedtopoorlydrainedwoilswillbeencountered.Generally,erosionpotentialalongthissegmentwillbelowto;oy,oderate.Permafrostdegradationpotentialislow.TherelativelyIevelnatureoftheterrainwillfacilitateconstruc-tionofanaccessroadwithoutundueerosionalproblems.Severalclear-waterstreamswillneedcrossing.Siltationmayoccurfromthesecross-ings,butsincetheywillbecrossedclosetotheirconfluenceswiththe"Ht-ladenSusitna,thisimpactwillbelow..omVeeDamsitetoSlideMountainthepotentialforpermafrostdegrada-tie'Disveryhigh.Thepoorlydrainedfine-grainsoilsencounteredareveryvulnerabletofrostheaving,whichwillentailmuchmaintenanceofthelineandroad.Thepotentialforscarringandruttingofthesurfaceishigh,andthesubsequenterosionmaycausesignificantsiltationinh'clemanyclearwaterstreamsinthisarea.FromSlideMountaintoPalmer,thecorridorencounterslesssensitivesoils.OnceoverTahnetaPasspermafrostbecomesincreasinglydiscon-tinuous,andwelldrainedsoilspredominate.Erosionpotentialislowtomoderateandconstructionofanaccessroadshouldpresentnoundueerosionalimpacts.SteepslopesintheupperMatanuskaValleymaypresentsomeerosionalproblems,buttheslopesaregenerallystable.Thinsoilsarealsocommon,andpotentialfordenudationofslopesbelowanaccessroadcutexists,'outshouldbeeasilypreventable.66 InthelowerMatanuskaValleysoilssusceptibletowatererosionareencountered,andlocationoftowersandroadwillhavetobeplannednotonlytopreventbankcutting,butalsotoavoidathreattotheinteg-rityoftheline.SincethisareaisalsotheState'sonlymajoragricul-turalarea,extensivecareshouldbetakentoavoidadverselyaffectinggoodquality,arablesoils.FromPalmertoPointMacKenzielargeareasofpoorlydrainedsoilswillagainnecessitategreatcareinlocationofthetransmissionline.Althoughpermafrostisabsent,scarringofthesoftpeatsoilsisstillapossibility,andthesubsequentsiltationofclearwaterstreamswillhaveanadverseimpactonaquaticlife.Theheavierclearingnecessaryinthisareawillalsocontributesomewhattosiltation;towhatdegreeisdependentuponthecareexercisedinminimizingdisruptionofthesoil.Vegetation:Ifa345kvtransmissionsystemisconstructed,thisalter-nativecouldrequireupto2,817acreSofclearing,510acresmorethanSusitha-l.Ifa230kvsystemisused,upto2,514acresofclear-ingwillbenecessary,454acresmorethanasimilarsystemalongSusitna-l.ThemajorityofthisclearingwillbeinthelowerMatanuskaValleyandalongthenorthshoreofCookInlettoPointMacKenzie.VerylittleclearingwillberequiredalongtheportionfromVeeDamsitetotheLittleNe1chinaRiver.Actualacresofclearingwillprobablybelessthantheabovefiguressincetheentirewidthoftheright-of-wayneednotbecleared.Theterrainisgenerallylevel;sotheaccessroadu'-beincorporatedintothelineclearingwithoutadditionalclearing.""eimmediateeffectofthisclearingwillbethedestructionofthevege-ta,ion.Themuchmoresignificantimpactwillbeuponerosionandwildlifehabitats.Inhillyterrain,mechanicalclearingmethodssuchasbulldozingwillcauseconsiderabledisruptionofthesoilandsubsequenterosionandstreamsiltation.Theuseofbrushbladeswillreducethiseffect.Onsteepslopeshandclearingwillmitigatetheotherwiseheavyerosionpotentiallikelywithmechanicalclearing.Toreduceavailablefuelforforestfires,andtoreducepotentialinfes-tationofhealthytreesbysprucebeetles(Dendroctonusrufipennis)andipsbeetles,slashmustbedisposedof.Thiscanbeeitherbysaleofmerchantabletimberorbyburning.Althoughburningwillreduceairqualitytemporarily,itismoreeconomicalandlessdamagingthanthealternatives.(SeeMitigatingMeasures.)67 Regrowthratesalongthiscorridorarefastenough,particularlyinthesouthernportion,towarrantperiodicsuppressionoftallgrowingtreeswhichposeahazardtothetransmissionline.Thepreferredmethodalongthiscorridorismanualapplicationofasuitableherbicide.Theamountofclearingtobemaintained,themodestregrowthrates,andhighcostoflabormakethisalternativepreferrableinthiscorridoroveraerialapplicationofherbicidesontheonehand,orhandcuttingofindividualtreesontheother.Ifproperapplicationtechniquesareadheredto(seeMitigatingMeasures),therewillbenootherimpactsotherthanthemaintenanceofasub-climaxvegetation.Accidentaloversprayingorwinddrift,orimproperdilution,resultinginunnecessarydestructionofvegetationandsprayingofwaterbodiesresultinginhabitatdestruc-tionforaquaticlifewillnotoccur.Sectionsneedingvegetationsuppres-sionoccurinthebottomlandspruce-poplar,lowlandspruce-hardwood,anduplandspruce-hardwoodforests,particularlyinthebottomlandspruce-poplar.Muskeg-bogareas,whichcompriseasignificantpro-portionoftheecosystemscrossedbythiscorridorwillneedlittleclearingandnovegetationsuppre~~ion.Lowlandspruce-hardwoodareaswillnotneedtobemaintainedasoftenasbottomlandspruce-poplar.InthemoisttundraecosystemsencounteredbetweenVeeDamsiteandtheLittleNelchinaRiver,destructionofvegetationwillbelimitedtothoseareasdirectlyoccupiedbytheroadbedandthetowerbases.Thiswillbeapermanentimpact,althoughsomerevegetationoftowerbasescanbeexpected.Destructionofthevegetativematinthetundraareaswillresultinlong5tingscarsunlesscorrectiveandpreventivemeasuresaretaken.Thiss(_crringcouldleadtosubsequentdegradationofice-richpermafrostanderosion.Firesresultingfromconstructionandoperation,unlesssuppressedquickly,willresultinextensivedestructionofvegetation.Theseecosystemsareadaptedtonaturalwildfires,andunlesstheoccurrenceofman-causedfiresisveryhigh,theyshouldrecuperateasquicklyastheywouldundernormalcircumstances.Wildlife:Alterationofvegetationpatternswillaffectwildlife.Thiscorridortraversesmanyareasofmooseconcentration,andmooseshouldbenefitfromtheintroductionofbrushresultingfromtheregrowthontheclearing.Sincetheclearingmustbemaintained,thisbrushareawilllastforthelifeoftheline.Mostbrushareasareintransition,changingfromthebrushphasetosomeotherphasenearertheclimacticphase.Th.brushinatransmissionclearingcanbecountedasamorepermanentsourceofbrowse.68 Animalsdependentuponclimacticforestsuchassquirrelswillsufferlossanddisplacement.However,theirfasterreproductiverateswillallowtheirpopulationstoadaptrapidly.Mostanimalswillbenefitfromtheedgeenvironment,offeringbothforageandcoverfromtheadjacentforestandbrush.Initially,animalmovementsmayoccuralongtheright-of-way,butasthebrushgrowsintoadensecover,thiswillbelimited.Inanyevent,thisimpactshouldbelowinthiscorridor.Constructionitselfwillaffectwildlife.Largermammalsmaytemporarilyleavetheareatoreturnaftertheconstructionactivity.Smalleranimalswillsufferlossofindividuals,butshouldrecuperaterapidlyonceconstructioniscompleted.Thedensityofforestinthiscorridorwillallowanimalstomoveonlyashortdistancetoavoidcontactwithconstruc-tionactivities.'v"getationsuppression,bywhatevermethod,willperiodicallyremovecoverfromalongtheright-of-way.However,duetothesurroundingcoveroftheunclearedforests,thisimpactwillbeinsignificant.Areasrequiringclearingcoincidewithmoosepopulations.Theresultingbrushwillbetotheirbenefit.CaribouontheuplandbetweentheSusitnaandLittleNelchinaRiverswillsuffersomedirectlossofforagefromthevegetationcoveredbytheroadbedandtowerbases.Ofmoreimport-c1etocaribouhabitatisthepotentialoverburningofkeywinterhrowse,andthesubsequentreductionofwinterrange.Sincethe•.dchinacaribouherdhasundergonedrasticreductionsinpopulation(tromanestimated61,000inthelate1960'stoanestimated4,000to5,000presently)anyadverseimpactoncaribouhabitatcanbeconsideredserious,Theaccessroadwillseriouslyaffecthuntingsuccessunlesshuntingisfurtherrestrictedinthisarea.TherewillbeonlyslightimpactonDallsheeprangeinTahnetaPass.Recreation:ThiscorridorapproachesnoStateorFederalparkorrecreationarea.HoweverJareas\vithahighrecreationaluseareencroachedupon.TheLakeLouiseareaisacomplexofinterconnectedlakessetuponagentle,rollinguplands,andreceiveshighuseforvacationing,fishing,andcamping.LakeLouiseitselfliesapproximately10mileseastofthisalternativecorridor.Increasedaccessandvisibilityoftransmissionstructureswillhaveimpactsupontherecreationaluse.SincetheareaisservedbyonlyoneroadtotheGlennHighway,anaccessroadwouldincreaseaccesstothearea.Thismaybeperceivedasanadverseimpactbypeoplealreadyowningorleasingsitesalongthelakeswhovaluetherelativesolitude,andmaybeperceivedasbeneficialbyfishermen,hunters,andotherswantingaccesstocabinsitesOntheselakes.69 FromDevilCanyontoSlideMountainthiscorridorwilltraverseareaspreviouslyaccessibleonlybyfootorair.Theimpactofanaccessroadhasbeendiscussedabove.ForaccesstothenorthofLakeLouise,increasedaccesswillallowgreateruseofthisuplandarea.Forhuntersparticularly,theincreasedaccessmaybeperceivedasdesirable.Accesswillbecontrolledbythelandmanagingagencyhavingjurisdic-tionovertheseareas.CulturalResources:ThiscorridorwillapproachthesitesoftheIndependenceMinesandKnikVillage,bothNationalHistoricalSites.ThecorridorwillavoidtheIndependenceMinesbyatleast8miles;sonoimpactonthissiteisanticipated.TheKniksitewillbeapproachedupto3to5miles;however,impactonthissitewillbelowtonone.Ifthefinalsurveydisclosesanunsuspectedarcheologicalsitealongtheright-of-way,thelocationofthelineortowerwillbealteredtoavoiddamagetosuchsites.Inadvertentdamagetoanarcheologicalsitewillreduceitshistoricalvalue.Atthesametime,discoveryofanarcheo-1014icalsiteduringsurveyorconstructionwillbeabeneficialaspect.ScenicResources:TherewillbeamediumtohighimpactonscenicqualityoftheTahnetaPass--upperMatanuskaValleyarea.Highexistingscenicquality,largenumber.ofviewersalongtheGlennHighway,andsomedifficultyinconcealmentofatransmissionlinecontributetothisimpact.DevelopmentofthelowerMatanuskaValley,whichhasalreadyaffectedtheintactnessofthatarea,willlessenvisualimpact.Theoppor-t';tiesforconcealmentaregreateralsointhelowervalley.LownumbersrfviewercontactsandeaseofconcealmentwillgreatlymitigatevisualHnpactfromPalmertoPointMacKenzie.Visualimpacthereislowtomedium.VisualimpactfromVeeDamsitetoSlideMountainislow.Thisisafactoroflowviewercontacts,lowtomediumexistingscenicquality,andtowardSlideMountainsomemeasureofconcealment.LandUseandResources:AlowimpactisexpectedonagricultureontheMatanuska.Thefinalroutecanavoidpresentlydevelopedlandandhighqualityundevelopedland.Eveniflandinproductionweretobecrossed,onlythelanddirectlyoccupiedbythetowerbaseswouldberenderedunfarmable.Muchoftheagriculturallandisdevotedtodairy-ingandhay.Therewouldbeaverylowimpactontheseuses.Truckfarmingwouldbeimpactedmorethandairyingorhaysincethepatternsofrowcropswouldbeaffectedbytowerlocations.70 Nosignificantimpactsareexpectedonpotentialforestryalongthisalternative,norareanysignificantimpactsexpectedonmineralsextraction.Social:Somesocio-economicimpactscanbeexpectedforPalmer,Wasilla,andtheseveralsmallcommunitiesalongthenorthshoreofCookInlet.Skilledlaborwillmostlikelynotbedrawnfromthesecommunities,althoughitispossiblethatunskilledlaborfromthesecommunitiesmightbeemployedontheconstructionphase.Localservicessuchasfoodandlodgingshouldexperienceanincreaseinbusiness,butthiswillbeatemporaryimpact,andduetotherelativelysmallamountofworkersneededandtheshiftingaspectoftheconstruction,aninsignificantimpact,also.Easementswillneedtobepurchasedoverprivatelyownedlands.Thiswillgivealumpsumpayment,whichwillbeapositiveimpactuponthelandowner.Futureriseinlandpl'icesandassessedtaxesduetoencroachingresidentialdevelopmentwilladverselyimpactlandownerswhohaveeasementsontheirland.Theywillpaytaxonlandtheycannotdevelop,atratesfarbeyondtheratesforundevelopedland.Incaseswherethismayoccur,somearrangementsuchasanincreasedlumpsumpaymentorannualpaymentsequaltothedifferenceintaxratesshouldbemade.ImpactsofAlternativeMatanuska-2Sils:ImpactsonsoilsfromSlideMountaintoPointMacKenzieare"denticaltothosedescribedunderimpactsonsoilsofalternativecorridorMatanuska-I.ThroughouttheentiresegmentfromWatanaDamsitetoSlideMountainbywayofGlennallen,thepotentialforpermafrostdegradationisveryhigh.Thepoorlydrainedfine-grainsoilsencounteredareveryvulnerabletofrostheaving,whichwillentailmuchmaintenanceofthelineandroad.Thepotentialforscarringandruttingofthesurfaceishigh,andthesubsequenterosionmaycausesignificantsiltationinthemanyclearwaterstreamsinthisarea.ParticularlysensitiveistheGulkanaanditstributaries.Thecorridorparallelsthissystemforapproximately50miles,andmultiplecrossingswillhavecumulativeeffectonsiltation.71 Vegetation:TheMatanuska-2alternativecouldrequireupto3,869acresofclearingifa345levsystemisconstructed.Thisis1,561acresmorethantheproposedSusitna-lcorridor.1£a230levsystemisused,upto3,454acreswillneedclearing,1,394acresmorethanSusitna-l,Actualacreageofclearingwillprobablybelessthanthesefiguressincenotalloftheright-of-wayneedbecleared,andtheterrainislevelenoughsothattheaccessroadcanbeincorporatedintothelineclearing.Theimmediateeffectofthisclearingwillbethedestructionofthevege-tation.Themuchmoresignificantimpactwillbeuponerosionandwildlifehabitats.Inhillyterrain,mechanicalclearingmethodssuchasbulldozingwillcauseconsiderabledisruptionofthesoilandsubsequenterosionandstreamsiltation.Theuseofbrushbladeswillreducethiseffect.Onsteepslopes,handclearingwillmitigatetheotherwiseheavyerosionpotentiallikelywithmechanicalclearing.Toreduceavailablefuelforforestfires,andtoreducepotentialinfesta-tionofhealthytreesbysprucebec'les(Dendroctonusrufipennis)andipsbeetles,slashmustbedisposedof.Thiscanbeeitherbysaleofmerchantabletimberorbyburning.Althoughburningwillreduceairqualitytemporarily,itismor",economicalandlessdamagingthanthealternatives.(SeeMitigatingMeasures.)Inthemoisttundraecosys[emcrossedfromWatanaDamsitetowithin10or20milesofPaxson,destructionofvegetationwillbelimitedtothoseareasdirectlyoccupiedbytheroadbedandthetowerbases.T,willbeapermanentimpact,althoughsomerevegetationoftower,csescanbeexpected.Destructionofthevegetativematintundraareaswillresultinlonglastingscarsunlesscorrectiveandpreventivemeasuresaretaken.Thisscarringcouldleadtosubsequentdegradationofice-richperma-frostanderosion.Firesresultingfromconstructionandoperation,unlesssuppressedquickly,willresultinextensivedestructionofvegetation.Theseecosystemsareadaptedtonaturalwildfires,andunlesstheoccur-renceofman-causedfiresisveryhigh,theyshouldrecuperateasquicklyastheywouldundernormalcircumstances.72 Wildlife:Alterationofvegetationpatternswillaffectwildlife.Thiscorridortraversesmanyareasofmooseconcentration,andmooseshouldbenefitfromtheintroductionofbrushresultingfromtheregrowthontheclearing.Sincetheclearingmustbemaintained,thisbrushareawilllastforthelifeoftheline.Mostbrushareasareintransition,changingfromthebrushphasetosomeotherphasenearertheclimac-ticphase.Thebrushinatransmissionclearingcanbecountedasamorepermanentsourceofbrowse.Areasrequiringclearingcoincidewithmoosepopulations.Theresultingbrushwillbetotheirbenefit.CaribouOntheuplandsbetweentheSusitnaandLittleNelchinaRiverswillsuffersomedirectlossofforagefromthevegetationcoveredbytheroadbedandtowerbases.Ofmoreimportancetocaribouhabitatisthepotentialoverburningofkeywinterbrowse,andthesubsequentreductioninwinterrange.DuetothedrasticreductioninthepopulationoftheNelchinaherd,(fromanestimated61,000inthelate1960'stoanestimated4,000to5,000in:n74)anyadverseimpactoncaribc>e'isaseriousimpact.Increasedaccesswillbeaseriousadverseimpactunlesshuntingisfurtherrestrictedinthisarea.AnimalsdependentuponclimacticforestsuchassquirrelswillsufferlossanddisplacementHowe',er,theirfastreproductionrateswillallowtheirpopulationstvadaptrapidly.Mostanimalswillbenefitfromtheedgeenvironment,offeringbothforagear,ucoverfromtheadjacentforestandbrush.Initially,animalmove->titsmayoccuralongtheright-of-way,butasthebrushgrowsintoadc-nsecover,thiswillbelimited.Inanyevent,thisimpactshouldbelowinthiscorridor.Constructionitselfwillaffectwildlife.Largermammalsmaytemporarilyleavetheareatoreturnaftertheconstructionactivity.Smalleranimalswillsufferlossofindividuals,butshouldrecuperaterapidlyoncecon-structioniscompleted.Recreation:ThiscorridorapproachesnoStateorFederalparkorrecrea-tionarea.However,areaswithahighrecreationaluseareencroachedupon.TheLakeLouiseareaisacomplexofinterconnectedlakessetuponagentle,rollinguplands,andreceiveshighuseforvacationing,fishing,andcamping.LalceLouiseliesapproximately35milestothewest.Sincethecorridorwillparallelanexistinghighway,itisunlikelythatitwillcontributegreatlytoincreasedaccesstothislakecomplex.73 ExceptfortheportionfromWatanaDamsitetoDenaliDamsite,thecorridorwillparallelexistinghighway.Threfore,itisnotexpectedthatthecorridorwillprovideaccesstosignificantlylargeareas.CulturalResources:ApartfromIndependenceMinesandtheKniksitediscussedunderalternativeMatanuska-l,theonlyNationalArcheol-ogicalsiteistheTangleLakesArcheologicalDistrictwestofPaxson.Carefulexaminationofthefinalroutewillminimizeanychanceofdisruptionofarcheologicalsiteswithinthisdistrict.ANationalHistoricalSite,SourdoughLodge,willnotbeapproachedenoughtobeaffected.Ifthefinalsurveydisclosesanunsuspectedarcheologicalsitealongtheright-of-way,thelocationofthelineortowerswillbealteredtoavoiddamagetosuchsites.Inadvertentdamagetoanarcheologicalsitewillreduceitshistoricalvalue.Atthesametime,discoveryofanarcheologicalsiteduringsurveyorconstructionwillbeabeneficialaspect.S'.'enicResources:ImpacttoscenicqualityfromDenaliDamsitetoPaxsonwillbehigh.Largenumbersofviewercontacts,littleopportunityforconcealment,andareasofhighexistingscenicqualityarefactorsinthishighimpact.FromWatanatoDenaliDamsites,visualimpactislow.FromPaxsontoSlideMountainvisualimpactwillrangefromlowtomoderate.Fortherestofthisalternative,visualimpactsareasdescribedfora1+''''rnativeMatanuska-l.~d.IldUseandResources:Littleornoimpactisexpectedonagriculture,fOl'estry,ormineralextraction.Thiscorridorwillparalleltheright-of-wayoftheAlyeskaPipelineandtheRichardsonHighway.Itwill,bydoingso,reinforcetheexistenceofautilitycorridorandsubsequently,thelocationoffuturerights-of-way.Somesavingsoftotalwidthofthiscorridorcouldbeachievedbysharingofrights-of-way.(SeeAlternativestotheProposedAction.)Social:Socio-economicimpactswillbeidenticaltothosediscussedforalternativeMatanuska-l,withtheexceptionoftwoadditionalcommuni-ties,GlennallenandPaxson.Sincethecorridorwillrunsoclosetoboth,itisverylikelythattheywillreceiveimpactsupontheirservicessuchaslodgingandfood.Thisisatemporaryimpact,andnotverysignificant.Somelocallabormaybeemployedduringconstruction,butthiswillprobablybeunlikely.74 Easementswillneedtobepurchasedwhereprivatelandmustunavoid-ablybecrossed.Thiswillresultinthelandownerreceivingalumpsumpayment,andwillprovidesomeinfluxofcapitaltotheseareas.ImpactsoftheDeltaAlternativeSoil:Thisalternativecrossessignificantlylargeareasofsoilshavingmoderatetohigherosionpotential.Therearetwosensitivesoilareas:1)Thepoorlydrained,ice-richpermafrostfoundthroughouttheentirelengthoftheroute.Thissoilisvulnerabletopermafrostdegradation,frostheaving,andruttingandscarringofthetopsoil.2)Thesecondsensitivesoiltypeisthefine-grainsoils,generallywelldraineduplandsoils,foundbetweenShawCreekandFairbanks.Thissoilisvulner-abletogulleying,unstableslopes,andwinderosion.Erosionfromeitherofthesetwosoiltypesmaycausesiltationinthe,,,anyclearwaterstreamsthataretdbutariestotheTananaRiver.Gen-erally,theseclearwatertributariesarelimitedtothosedrainingthenortheastportionoftheTananaRivervalleyinthisarea.TributariesoftheTananafromtheAlaskaRangearesiltladenandwillnotbesignificantlyimpactedfromerosion.Localproblemareaswillbeencountered.NorthofSummitLake,inIsabelPass,isanareaofthixotropicsoilswhichbecomeplasticunderseismicshock.Unlessthissoilcanbefeasiblycircumvented,trans-ml~siontowersinthisareawillbeunderhigherthannormalseismicsk.ThroughtheIsabelPass,rockysoilsinterspersedwithbedrockandtaluswillpresentproblemsinplacingoftowerfoundationsandaccessroad.Excessivecuttingandfillingforanaccessroadthroughthisarea,inconjunctionwiththinsoilsorunstableslopes,cancausesevereerosion.Alarge,extremelymarshyareaaroundtheShawCreekconfluencewillbeencountered.Towerfoundationswillneedspecialattentionandtheaccessroadwillneedspecialdesign.Frostheavingwillbesevereinthismarshysoil.Vegetation:TheDeltaalternativecouldrequireupto1,737acresofclearing,288acresmorethanNenana-I.Theactualacreageclearedwillprobablybelessthanthesefiguressincetheentirewidthoftheright-of-wayneednotbecleared.Inareaswhereclearingisrequired,theterrainislevelenoughtopermittheaccessroadtobeincorporatedintotheliLeclearing.75 Themajorityoftheclearingwillbedoneintheuplandspruce-hardwoodandbottomlandspruce-poplaralongthelowerDeltaRiverandtheTananaRiver.Toreduceavailablefuelforforestfires.andtoreducepotentialinfesta-tionofhealthytreesbysprucebeetles(Dendroctonusrufipennis)andipsbeetles,slashmustbedisposedof.Thiscanbeeitherbysaleofmerchantabletimberorbyburning.Althoughburningwillreduceairqualitytemporarily.itismoreeconomicalandlessdamagingthanthealternatives.(SeeMitigatingMeasures.)Theimmediateeffectofthisclearingwillbethedestructionofthevege-tation.Themuchmoresignificantimpactwillbeuponerosionandwildlifehabitats.Inhillyterrain,mechanicalclearingmethodssuchasbulldozingwillcauseconsiderabledisruptionofthesoilandsubsequenterosionandstreamsiltation.Theuseofbrushbladeswillreducethiseffect.Onsteepslopes,handclearngwillmitigatetheotherwiseheavyerosionpotentiallikelywithmechanicalclearing.Inthealpineandmoisttundr?ecosystemsfoundfromWatanaDamsitethroughIsabelPassandtheAlaskaRange,destructionofvegetationwillbelimitedtothoseareas-iirectlyoccupiedbytheroadbedandthetowerbases.Thiswillbeapermanentimpact,althoughsomerevege-tationoftowerbasescanbeexpected.De..ructionofthevegetativematintundraareaswillresultinlong1tingscarsunlesscorrectiveandpreventivemeasuresaretaken.Lhisscarringcouldleadtosubsequentdegradationofice-richperma-frostanderosion.Firesresultingfromconstructionandoperation.unlesssuppressedquickly,willresultinextensivedestructionofvegetation.Theseeco-systemsareadaptedtonaturalwildfires.andunlesstheoccurrenceofman-causedfiresisveryhigh.theyshouldrecuperateasquicklyastheywouldundernormalcircumstances.Wildlife:Theareasrequiringthemostclearingcoincidewithmanyareasofmooseconcentration,andmooseshouldbenefitfromtheintroductionofbrushresultingfromtheregrowthontheclearing.Sincetheclearingmustbemaintained,thisbrushareawilllastforthelifeoftheline.Mostbrushareasareintransition.changingfromthebrushphasetosomeotherphasenearertheclimacticphase.Thebrushinatransmissionclearingcanbecountedasamorepermanentsourceofbrowse.76 ScenicResources:ThiscorridorwillhavevisualimpactsrangingfromhighalongtheDenaliHighwayandthroughtheIsabelPass-AlaskaRangearea,moderatefromDonnellyDometotheSalchaRiver,andtolowfromtheSalchaRivertoFairbanks.SincenearlytheentirecorridorisexposedtoviewersfromtheDenaliandRichardsonHighways,thevari-ablesaretheexistingscenicqualityandtheopportunitiesforconceal-ment.Alongthisalternative,generallythehighertheexistingscenicquality,thelesstheopportunityforconcealment.LandUseandResources:Noimpactsareexpectedonmineralsextrac-tion.TheareaaroundBigDeltaandDeltaJunctionisapotentiallymajoragriculturalarea,particularlyingraincropssuchasbarley.Crossingofgoodqualityarablelandwillresultintheremovalfromproductionofthelandoccupiedbythetowerbases.Rowcropswillbemoreaffectedthanfieldcropsinthatpatternsoftillingandharvestingwillbemoredisruptedbytowerlocations.AlongthelowerDeltaRiverandtheTananaRiverthereispotentialforforestry,particularlyinthebottomlandspruce-poplarecosystems.TheDeltaalternativewillhavelittleeffectonforestry,apartfromminimaluseasloggingroadsorfirebreaks.Merchantabletimberfromclearingoperationscanbedisposedofbysale.Theproximityofahighwayandriverwillfacilitatesalvageoflogs.ParallelingoftheAlyeskaPipelineandtheRichardsonHighwaywillreinforcetheutilitycorridoralongtheDeltaandTananaRivers,andwi"affectlocationoffuturerights-of-way.thetotalwidthofthisutilitycorridorcanbereducedbysharingofrights-of-way.(Seej-,;ternativestotheProposedAction.)Social:ThetownsofPaxson,DeltaJunctionandBigDeltawillbenefitfromuseofservicessuchasfoodandlodgingbyconstructionworkers.Itisunlikelythatmuchofthelaborneededforconstructionwillbedrawnfromthesmallercommunities.LoggingoftimberandclearingcontractswillaffecttownsalongtheTananaRiverbyprovidingjobsandcapitalfromsalesoftimber.Thiswillbeashort-livedimpact,however.Someeasementsacrossprivatelandmayneedtobepurchased.ThemajorityofthealternativecanberoutedalongtheutilitycorridoralongtheAlyeskaPipeline.Purchasesofeasementwillprovidealumpsuminfluxofcapitaltotheaffectedlandowners.Thisinfluxistemporary,unlessarrangementsaremadeforyearlypayments.78 ThelargenumbersofcaribouintheNelchinaherdsouthoftheAlaskaRangewillsuffersomedirectlossofforagefromthevegetationcoveredbytheroadbedandtowerbases.Ofmoreimportancetocaribouhabitatisthepotentialoverburningofkeywinterbrowse,andthesubsequentreductioninwinterrange.DuetothedrasticreductioninthepopulationoftheNelchinaherd,(fromanestimated61,000inthe1960'sto4,000to5,000in1974)anyadverseimpactisaseriousimpact.Increasedaccesswillseriouslyaffect-theherdunlesshuntingisfurtherrestricted.TherewillbeonlyslightimpactonDallsheeprangeinIsabelPassandthecanyonoftheDeltaRiver.Animalsdependentuponclimacticforestsuchassquirrelswillsufferlossanddisplacement.However,theirfasterreproductiverateswillallowtheirpopulationtoadaptrapidly.Mostanimalswillbenefitfromtheedgeenvironment,offeringbothforageandcoverfromtheadjacentforestandbrush.Initially,animalmovementsmayoccuralongtheright-of-way,butasthebrushgrowsintoadensecoverthiswillbelimited.Inanyevent,thisimpactshouldbelowonthiscorridor.Constructionitselfwillaffectwildlife.Largermammalsmaytemporarilyleavetheareatoreturnaftertheconstructionactivity.Smalleranimalswillsufferlossofindividuals.butshouldrecuperaterapidlyonceconstructioniscompleted.Thedensityofforestinthiscorridorwillalk-vanimalstomoveonlyashortdistancetoavoidcontactwithconstruc-tionactivities.Vegetationsuppression,bywhatevermethod,willperiodicallyremovecoverfromalongtheright-of-way.However.duetothesurroundingcoveroftheunclearedforests,thisimpactwillbeinsignificant.Recreation:ThiscorridordoesnotinfringeuponanyFederalorStateparkorrecreationarea.SincetheDeltaalternativeparallelsexistinghighwaysandtheAlyeskaPipeline.itwillnotprovidenewaccesstoanysignificantlylargearea.Useoftheaccessroadisdependentuponregulationsimposedbythelandownersorlandmanagingagency.CulturalResources:ForthesegmentfromWatanaDamsitetoPaxsontheimpactsareasdescribedunderimpactsofalternativeMatanuska-2.FromPaxsontoFairbankstherearenoNationalArcheologicalorHistori-calSites.Ifthefinalsurveydisclosesanunsuspectedarcheologicalsitealongtheright-of-way,thelocationofthelineortowerswillbealteredtoavoiddamagetosuchsites.Inadvertentdamagetoanarcheo-logicalsitewillreduceitshistoricalvalue.Atthesametime,discoveryofanarcheologicalsiteduringsurveyorconstructionwillbeabeneficialaspect.77 MITIGATIONOFIMPACTSMostmitigatingmeasuresarebasicallystandardpracticesstringentlyenforced.IfbasicapplicableregulationsissuedbytheFederal,State,andlocalgovernmentsregardingenvironmentqualityareadheredto,mostimpactsaffectingairandwaterqualitywillbeminimized.Applicationofpracticesandguidelinessuchasthoseissuedin"EnvironmentalCriteriaforElectricTransmissionSystems", ajointDepartmentoftheInterior,DepartmentofAgriculturepublication,willreducevisualandenvironmentalimpacts.Consultationwithagenciesproficientincertainareasofconcern,suchastheSoilConservationServiceandtheStateDepartmentofFishandGame,willprovidefurtherguidanceonmitigationofimpacts.Morespecificmitigatingmeasures3·ediscussedbelow.ItmustberememberedthatmanyoftheseareSlandardpracticesintendednotonlytominimizedamagetotheenvironment,butalsotoprotecttheintegrityofthetransmissionline.SoilsSinceitisexpectedthatmostdamagetosoilswilloccurduringtheconstructionphase,theconstructionschedulecanbearrangedsothatcor~'derableamountsofthework,particularlythoserequiringtheuseofanaccessroad,suchasdeliveryofmaterials,canbedoneinwinterahuspring,whenthegroundisleastvulnerabletophysicaldisturbances.Temporaryroadswillbeavoidedasmuchaspossible;accessroadswillbebuilttoastandardapplicabletotheexpecteduse.IfsodesignatedbytheStateDepartmentofHighways,somesectionsofaccessroadswillbebuilttosecondaryroadstandards.Notallsectionsofthelinewillrequireanaccessroad;particularlysensitiveareasmaybeprotectedbytheuseofhelicopterconstructionandmaintenance,ortheuseofwinteraccessroadsandhelicoptermaintenance.Itshouldberecognized,however,thatdependenceonaerialmethodsleavestheconstructionand/ormaintenanceprogrammorevulnerabletoweatherconditions.OnemajorsectionwillbeconstructedwithoutaccessroadsfromDevilCanyontoHealy.Forgroundwork,roadsmustbeadequatelyconstructedtoavoiderosion,slopeinstability,degradationofthepermafrost,andalterationofdrainage.Gravelorotherinsulatingmaterialshouldunderlaypermanentaccessroadsonpermafrostarea;culvertsandbridgeswherenecessaryRI1 shouldbeplacedtoavoiddisruptionofdrainageandpossibleicingconditions.Slopesoncutsandfillsshouldbeofpropergradientandrevegetatedassoonaspossibletopreventerosionandslumping.RevegetationwillbedonewithspeciesrecommendedinthevegetativeguideforAlaskapublishedbytheSoilConservationService.Forgroundworkoffoftheaccessroad,orwherenoaccessroadwillmachinerycompatibletothesurfaceshouldbeused.Forshallowpermafrostareas,softmuskegandbogs,andhighlyerosivesoils,machinerywithlow-pressuretreadsortiresshallbeusedtoavoidscarringthevegetativematandincurringsubsequenterosion.Onsensitivesoils,suchasice-richsoilswithashallowpermafrosttable,disturbedsoilwillbeprotectedwithanorganicinsulatingmulch,suchasstraw,orwhenavailable,chippedslashfromtheclearing.Revegetationwithappropriatecoverplantswillimmediatelyfollowconstruction.Toreducethelikelihoodofdisturbanceofmarshysoils,matsofslash,bogs,orothermaterialswillbeused.Onerodableslopes,nobulldozing,illbedoneonslopesgreaterthan35%.Allcutsandfillsshallbeangledbacksufficientlytominimizeslumpingandimmedatelyseededwithappropriateplants.Soddingorfabricmatsmayneedtobeusedinsomecasestominimizeerosionuntilrevegetationcancontrolslopeerosion.Culvertsandwaterbreakswillbeplacedtoreducewaterflowoverthebareroadbed.Nomachineclearingwillbepermittedwithin100feetofanystreambed.Toprotecttheintegrityofstructuresinextremelymarshysoilsorsoilswithashallowice-rich,permafrosttable,andtominimizeuseof,..eaccessroadformaintenanceoftowerfootingsonthesesoils.attransferdevicesmaybeusedifnecessarytokeeptowerfootingsandguysfrozenintoplace.Thisisespeciallyimportantinthosestretchesnothavinganaccessroad.Bykeepingpoorlydrainedsoilsandtheshallowactivezonearoundtowerbasespermanentlyfrozen.eliminatingfrost-heavingofanchorsandsettlingoffoundationsduetochangesinthepermafrost.Thereareseveraltypesofthesedevicesinuse;theiruseiswidespreadalongtheAlyeskaPipelingwhereelevatedsectionsofpipearevulnerabletosettling.Agooddiscussionofseveraltypesofthesedevicesisfoundinthearticle"SettlingaProblem.ofSettling"•intheNorthernEngineer.Vol.7no.1.Thebasicprincipleofthesedevicesisthatof"pumping"heatfromthesoiltotheair.Year-roundoperationwouldrequireanactualpumptokeepcoolantflowing,butseveraltypesusenopump,relyinginsteaduporthedifferencebetweensoilandambientairtemperaturesinwinterandone-wayflowofcoolanttoretardheattransfertothe81 soilinsummer.Theseheat-transferdevicesmayprovidethebestavailablesolutiontotheproblemofsuitablefootingsandanchorsforstructuresinmuskeg.Firecontrolwillbequickandefficienttolimitfirestosmallareas.Firecontrolmethodsandmachineryshouldnotultimatelycausemoredamagethanthefiresthemselves;soildisruptionbyfirecontrolmustnotaggravatesoildisturbancealreadycausedbyafire.Aerialcontrolandgroundvehicleswithlow-pressuretreadswillbeusedwhereneeded.Crewswillbeinstructedonfiresafety.Extinguishingtoolswillbeonhand;machinerywillbesuitablymaintainedtominimizesparking.Workwillgoonaspecialbasisduringhigh-riskperiods.Thepermanentaccessroadcandoubleasafirebreakandafire-controlroadforcon-tinuingwildfiremanagement.Onunbridgedstreamcrossing,gravelfordswillbeconstructedwherethebottomisnotalreadygravel.Notreesshallbefelledoryardedacrossstreams.Nowastematerialwillbedumpedintostreamsorabandonedontheirfloodplains.Towerswillbelocatedwellawayfromstreamsnotonlytoreducethepotentialforerosion,butalsofortheirownsafety.VegetationOnlythenecessaryvegetationwillbeclearedtominimizeimpactandcost.Photogrammetricidentificationofclearingzoneswillbeused;this.~chnique,alreadyinusebyBonnevillePowerAdministration,usesacombinationoffactors,includingspacingoftowers,linesag,topography,profiles,andgrowthrates,todetermineexactlywhichtreesneedtobeeliminatedinaforestedarea.DesignationoftheminimumsafeclearingwillbeinkeepingwiththeNationalElectricSafetyCode.Clearingwillbewithbrushbladesonbulldozerstoreduceunnecessary'disruptionofvegetation.Nobulldozingwillbepermittedonslopesgreaterthan35%.Clearingonsteepslopeswillbebyhand;stumpsandrootswillbeallowedtoremaintohelpkeepslopesstable.Slashwillbeimmediatelychippedtoprovideerosioncontrolwherenecessaryorburnedtoavoidpotentialinsectepidemicsandtoreducefirehazard.Disturbedareaswillbegradedbacktomergewiththecontoursoftheland,andfertilizedorrevegetatedifnecessarytoprovideagroundcover.Inmanycases,chippingofbrush,averysuitablemethodofreducingsoilerosioninthecleanng,willalsoprovidesomeincreaseofinsulationinareasofshallowpermafrost.Firehazardwillbelow,sincethechipswillusuallybeinwetsoilsintheseconditions.82 Revegetationofclearedareascanbewithplantspeciesthatwillenhancehabitatforanimals,yetcansuccessfullydominatetaller-growingspecies.Typicalofthesespeciesaregrassesandlegumes.Revegetationwillbecarriedoutinaccordancewiththe"VegetationGuideforAlaska"presentlyusedbytheStateDepartmentofHighways.Thosesectionsofclearingneedingperiodicmaintenancetokeepdowntall-growingtreeswillbeclearedinsuchawayastominimizefurthersoildisruption.Ifmechanicalmethodsareused,selectivecuttingispreferableoverbrushhogsorbrushbladesontractors,whichnotonlycanbedestructivetothesoil,butinefficientalsointhatlittleselectivecuttingispossible.Ifherbicidalcontrolistobeused,properapplicationmethodsandproperherbicidemethodswillbeused.Aerialapplicationwillnotbeused;manualapplicationisnotonlyveryselective,butaccidentalmisapplicationislesslikelytooccur.Herbicideswillnotbeappliednexttostreamsorlakes;abufferstripwillbeleftuntreatedadjacenttowaterbodies.Applicationwillbeofacoverageanddilutionappropriatetothevegetationbeingtreated.Firecontrolwillbeasdiscussedintheprecedingsectiononsoils.WildlifeApolicyofminimalclearingofvegetationshouldhavetheleastimpactuponwildlifeintermsofdestructionofhabitat.Avoidanceofuniquehabitat,orhabitatofrareandendangeredspecieswillminimizeimpactor'heseimportant,butusuallylocalized,areas.Seasonalschedulingofconstructionwillminimizecontactswithmigratingmammals,although"USmayconflictwithwinterconstructioninareasusedbywinteringcaribouormoose.Anyaccessroadswillbedesignedtominimizerivercrossings,whichshouldreducesiltationcausedbyfordingmachinery.Wherepossible,drainagewillbepreservedthroughproperplacingofculvertsandbridges.Borrowpitswillbelocatedtoavoidsiltationofclearwaterstreamsandlakesandsubsequentimpactsonaquaticecosystems.Spillsoffuel,oil,andotherchemicalswillbeavoided,particularlyifstreamsorlakesmaybeaffected.Herbicides,ifused,willbeappliedproperly.Wildfirecontrolwillbeasdiscussedinthesectiononsoils.Harassmentofwildlifebygroundvehicles,planes,orhelicopters,eitherdeliberateorinadvertantwillbeminimizedbystrictenforcementofvehicleuseandaircraftusebyeitherthecontractorsorthesupervisors.Huntingandtrappingactivitiesofworkcrewswillbecontrolled.TheAlyeskaPipelinecampsrestrictfirearmspossessiontocontrol83 huntingandharassment,nottomentionaccidentalshootings.TheAlyeskaPipelinecampandconstructionareashavealsobeenclosedtohuntingandfishingbytheAlaskaStateDepartmentofFishandGame.Increasedexposureofwildlifetohuntingortrappingbecauseoftheincreasedaccessofaserviceroadcanbecontrolledtoadegree,ifdeemednecessarybygamemanagementagencies.Accessroadheadscanbebarricadedorconcealed,breakscanbedesignedontheaccessroadtolimitusebystandardfour-wheeldrivevehicles,andtheroadcanbeposted.However,itisnotexpectedthatsuchaccess-controlmeasureswillentirelysucceed.Inmostareas,AlaskaPowerAdministrationfavorsmultiple-useoftheright-of-way;finalregulationofaccesswillbeatthediscretionofthelandownerorland-managingagency.ExistingDevelopmentsToavoidpreemptionofprivatelands,thefinalroutewillbeflexibleenoughtocircumventsmallblocksofprivateland.Largerprivatelyownedsectionswillentailapurchaseofeasement.Allofthealternativecorridorscanavoidcommunitiesenroute.SectionsofthelinedeemedhazardousbytheFAAwillbcadequatelymarkedasoutlinedinPart77,FAAregulations"Obj8ctsAffectingNavigableAirSpace".Theprojectwillprovideservicesforitsworkers,thusavoidingthepotentialstrainingofacommunity'sservices.However,thelocalCCdmunitiesshouldbenefiteconomicallyfromfringeservices,such.,entertainment,andservicestotransmissionline-relatedworkersoutsideoftheactualproject.ScenicQuality-RecreationTheobtrusivenessofatransmissionlinecanbelessenedbyproperdesignandlocation.Inforestedareas,placingtheclearingfarenoughfromaparallelhighwayorrailroadissufficienttoconcealthetransmissionline.Inareashavingshortertrees,usingthetopographytoconcealalinebehindridges,inswales,andalongbreaksinslopeswillhelptolessenitsvisibility.Incompletelyopenareas,theonlyalternativesareusingacombinationoftopographyanddistancetoconcealaline,ortokeepitclosetotheroadifitcannotbeconcealed.Bykeepinganobviouslinenexttoaroad,onecanwalkunderthelinetogetanunobstructedviewofsceneryontheothersideofit;merelykeepinganunconcealablelineashortdistancefromaparallelroaddoesnotlessenitsobtrusiveness,anditprecludesgettingaclearviewofscenerybeyondit.84 Othertechniquesofconcealingormitigatingthepresenceofalinearetoavoidclear-cutsforclearings,butinsteadtofeatherbackthebreakbetweenoriginalforestandclearing;useofphotogrammetricselectiveclearingwilleasetheabruptappearanceofclearings.Whereroadcrossingsarenecessary,itisbesttocrossatlessthanrightanglesandtoleaveabufferstripoforiginalvegetationtomasktheright-of-way.Thismightinvolveusingtallerthanusualtowersoneithersideofthehighwaytoprovidetheadditionalclearance.Placinglinesonridgessilhouettesthem,andwillbeavoided;ridgecrossingsarebestputinnotchesorlowspots.Wheneverpossible,alinewillavoidanareaofparticularscenicquality;especiallywhenanunconcealedlinehastobeseenagainstaveryscenicbackground.Wheresuchconflictsareinevitable,extradesignandlocationattentioniscalledfortoreducetheobtrusivenessoftheline.Forsakinganaccessroadforhelicoptermaintenance,minimalright-of-wayclearance,alternativetowerdesignsandspecialfinishesonlinecomponentshelpconsiderably.Replacingthestandardguyedtowerdesignswithalternativewood-poleandmetaldesignsconsideredtobemoreaesthetic,usinganodizedorpaintedtowers,andusingdullfinishconductorsminimizethevisibilityofthelinecomponents.Inallcases,alltemporarystructureswillberemoveduponcompletionoftheconstructionphase.Smallerrecreationareasandscenicareaswillbeavoidedaltogether;usuallytheserecreationareasareState-mc.:ntainedwaysideparksofrelativelysmallsize.Archeologicalsiteswillbeidentifiedonpreliminarysurveysofthechosencorridorandthefinalrouteadjustedaccordinglytoavoiddisruptionofthesesites.Wheneverpossible,existingrights-of-wayshouldbesharedorparalleledtoavoidtheproblemsassociatedwithpioneeringacorridorininaccessibleareas.Trailsinthese"inaccessible"areasshouldhowever,beavoided;preservingwildernessqualityentailssharingorparallelingallrights-of-wayexcepttrails,andfromthese,linesshouldbeshieldedasmuchaspossible.85 ADVERSEENVIRONMENTALIMPACTSAllgenerationofpowerwillcreateadverseimpacts,alltransmissionofpowerwillcreateadverseimpacts;allgenerationsites,exceptforlocalgeneration,needatransmissionsystem.Thedegreeofadverseimpactofatransmissionlinewillvarywithitslength,thecharacteroftheterrain,andthecareexercisedindesign,construction,operation,andmaintenance.AdherencetoregulationsandguidelinesissuedbytheNationalEnviron-mentalPolicyActof1969,theWaterQualityAct,andrelevantStateandlocalagenciesandapplicationofmitigatingmeasureSasoutlinedonthepreceedingsectionwillreduceunavoidabledetrimentalimpactstoaconsiderabledegree.However,someunavoidableimpactsareinevitable.Theseimpactsareoftwokinds:Thoseresultingfromtheconstructionactivities,andthol'inherentintheexistenceofatransmissionline.Unavoidableimpactsduetoconstructionactivitiesareusuallytemporary;theseincludeeffectssuchasdisYuptionofthesurfacevegetationandsubsequenterosiononslope",disruptionofanimalhabitatduetohumanpresence;and10s5ofvegetationduetoclearing.Thedegreeoftheseimpactswilldependuponthemitigationmeasurestaken,timingoftheconstructionphase,andecologicalfactors;theseimpactswillIe."enorceaseafterconstruction,asregrowthofvegetationand~·'invasionoffaunaoccurs.Unavoidableimpactsofamorepermanentnatureassociatedwithmainten-anceandoperationofthetransmissionlineincludemodificationofhabitatduetoamaintainedclearing;increasedaccessandsubsequentimpactsofincreasedaccess;influenceonexistingandfuturelanduse;influencesonexistingandfutureutilitycorridors;andveryimportantly,impactsonsThemaintenanceofaclearingthroughforestedareaswillhaveimpactsonwildlifeforthelifeofthetransmissionlines.Animalsdependentuponsuccessionalvegetationforbrowse,suchasmooseandsnowshoehare,willbenefitbytheintroductionofbrushintoanotherwiseforestedarea.Animalsdependentuponclimaxforestforhabitat,suchasredsquirrel,willsufferareductionofhabitat.Ingeneral,bothoftheseimpactswillbeinsignificantduetothesmallratioofaffectedlandtotheareaofunaffectedforesttraversedbyatransmissionroute.87 Increasedaccessduetotheexistenceofatransmissionlinewilldependuponthetypeofaccessusedtotheline,thedegreeofpresentaccess-ibility,theareaofinaccessiblelandopenedup,andtheattractionforactivitiesotherthanlinemaintenance.Somesectionsofthelinewillhavenoaccessroad;somewillbeservicedbytemporaryconstructionroadsorwinterroads;somesectionswillbeservicedbyanaccessroadsuitableforfour-wheeldrivevehicles.Thus,accesswillbeeffectivelydeniedtovehiclesunabletonegotiatearoadofthisstandard,andinmanyareas,toallvehiclesexceptall-terrainvehiclesoraircraft.Iftheareaisalreadysuitablyservedbyanexistingroadofhigherstandards,itwouldbeexpectedthatatransmissionlineaccessroadwillnotappreciablyaffecttheexistingaccess.Also,itwouldbeexpectedthatlargeareasopened"f>byanewaccessroadwouldreceiven!\..lreimpactsthansmallerareas;huwever,itcanalsobereasonedthatlargerareascanabsorbthegreaterimpactsofincreasedaccessmoreeasilythansmallerareas.Ifotherfactorsareconsideredequal,impactsofincreasedaccesswilldeyoulduponthearea'sattractivenessforhunting,packing,camping,andslghts('eing.AlaskaPowerAdministrationpresentlyfavorsmultiple-useoftransmissionrights-of-way.Sincemostoftherights-of-waywillbeeasementsonSh+eandprivatelands,andlandsmanagedbyotheragencies,deter-minationofaccesswillbelefttothelandownersormanagers.Therewillbeanunavoidableimpactonpresentandfuturelanduse;thedegreeofthisimpactisafunctionoftheexistinguseandthepotentialusesofnotonlythelandoccupiedbythetransmissionline,butalsotheadjacentlands.Presently,thereislittleagricultureorforestryalongthealternativecorridors;residentialareasarelargelylimitedtotheAnchorage-PalmerandFairbanksareas.However,futurepatternsoflandusewillchange;agriculturalpatternsadjacenttoatransmissionlinewillbeaffectedsomewhat,dependingonthecropandthemethodofagriculture.Sincethetransmissionlinewillprobablypredateagriculturallandusealongthecorridor,thisimpactwillbeslight,andprobablybeneficial,sincearight-of-waywouldprovideclearedlandatlittleornoexpensetothefarmer.Irrigationandtillingmethodswillhavetoadaptthemselvestothespacingofthetowers;landoccupiedbythetowerbaseswillbeunusable,butthislandisasmallfractionoftheright-of-way.88 Forestryispresentlylimitedbyphysical,economic,andownershipfactors.Presentforestryareascaneasilybecircumvented;potentialareasmaybenefitfromtheexistingaccessroadofthetransmissionlinenotonlyforlogging,butalsoforfirecontrol.Theexistenceofatrans-missioncorridoringeneralwillhaveaminimalimpactonforestry.Presentresidentialareaswillbeunaffectedbyanyofthealternativecorridors,potentialresidentialareasadjacenttoanexistingtransmissionlinewillaccommodatethemselvestoitspresence.Thevoltageofthetransmissionlineprecludesdirectservicetosmallcommunities;thesewillhavetobeservedbylowervoltagedistributionlines,emanatingfromexistingorfuturemajorsubstations.Thepotentialforservicetosmallcommunitiesisasignificantimpactinthatthesecommunitiesmaystronglydesiretotapthetransmissionline;iftheyareservicedbythetransmissionline,theywillessentiallybecomepartoftheintercon-nectedsystem.Sincethecostofpowerwillmostlikelydecreaseinthesecommunitiesafterinterconne''ion,localgrowthcanbeexpanded.Theexistenceofatransmissioncorridormaytendtoattractfuturecorridors;toaconsiderableex~ent.thisisabeneficialimpactinthatitismoreeconomicalforrights-of-waytobesharedortobeadjacent;thereisalessenedlikelihoodr:.flargeareasofwildernesstobecutintoamultitudeofsmallerareasbyredundantrights-of-way;andthepossibilityexistsfor"symbiotic"useofaright-of-waybytwodifferenttypesofutilities.Examplesaretheuseofaccessroadsfortra.'portationandtheelectrificationofrailroadsandpipelines.In''''Tidorslimitedbyphysicaland/orpoliticalconstraints,suchastneNenanaCanyonthroughtheAlaskaRange,proliferationofrights-of-waywillleadtocongestion;incasessuchasthis,itismostdesirabletosetafuturepatternbyattemptingtoutilizeexistingcorridorstominimizepotentialcongestion.Oneofthemostsignificantunavoidableadverseimpactswillbeuponscenicquality.Atransmissionlinewillalwayscauseadetrimentalimpact;thedegreeofthisimpactisdeterminedbythevisibilityandobtrusivenessofthetransmissionlineasseenbythemajorityoftheviewers.Sincemostoftheviewersofthealternativecorridorswillbeontheexistingtransportationroutes,itisinferredthatincreasedvisibilityandobtrusivenessfromtheseroutescanbeequatedtogreatervisualimpact.Visualimpactonviewersfromthetransportationrouteswillbeminimized,fromtotalscreeninginheavily-forestedareas,tocamouflagingbymeansofcoloredtowersandintelligenttowerlocation.89 However,itisimpossibletohideanylinefromallviewersfromalldirections.Anytransmissionlineiseasilyvisiblefromtheair;placingalineawayfromaroadtohideitfrommotoristswillnotconcealitfromhunters,hikers,andcampers,towhomthelinemaybeespeciallyobtrusive.Thisdilemmabecomesmoresevereinopencountry,particularlyinscenicsurroundings.Insummary,adverseenvironmentalimpactswillbe:clearingofvegetationfromasmuchas3747acres.subsequentperiodiccontroloftheregrowthontheclearingcreated.permanentremovalofvegetationfromtowerbases,accessroads,andanyfuturesubstationstobeaddedtothesystem.impactstosoilfromconstructiOl.andmaintenanceoperations.impactstofisheriesinclearwaterstreamsaffectedbyconstructionandmaintenance.impactstowildlife,bothbeneficalandadverse,stemmingfromtheaboveeffectsofconstructionandmaintenance.visualimpactstoscenicandrecreationalresourcesfromTalkeetnanorthtoHealy.effectsonairqualityduetoburningofslashresultingfromclearingoperations.90 RELATIONSHIPBETWEENSHORT-TERMUSESOFTHEENVIRONMENTANDLONG-TERMPRODUCTIVITYThetransmissionlinecanbeassumedtohaveaverylonglife;aslongasloadsaree:>..'})ectedtoincrease,astheyare,andaslongastheUpperSusitnaprojectisaviablesourceofpower,thetransmissionroutecanbeconsideredoperative.Individualcomponentswillbereplaced,anditisforeseeablethatthelineitselfmaybeupgradedtohighervoltagesandcapacity,butitwillstillbeessentiallythesametransmissionsystem.Thebulkoftheimpactsontheenvironmentofthelinewillbeencounteredduringtherelativelyshortconstructionphase.Ofthelong-termeffects,somewouldterminateimmediatelyorshortlyaftertheretirementoftheline.Someoftheseeffectswouldbethosespringingfromaccessroadmaintenance,vegetationcontrol,noiseandelectromagneticinterference,(seeAppendixI"Hazards")andvisualimpact.Otherimpactswillbe"imprinted"intotheenvironmer,·.Wildlifepatternsmayhavebeenaflectedbycontinualhuntingorhabitatmodification;thesepatternswilllingerforaconsiderabletimeafterapossibleremovaloftheline.Vegetationpatterns,alteredbycuntinualmaintenanceorintroductionofgrassesorothernonnativeplants,maycontinueforaverylongtime.Uncheckedregrowthoftheclearingwilleventuallyresultinsuccessionalvegetationcl03ertothestageofthesurroundingforests;thisregrowthwillentailhabitatmodificationsoppositetothosecausedbytheoriginalclearing,butofcourseoveramuchlongertimeperiod.'I1'eaboveassumesthatthetransmissionright-of-waywillretainitsullginalfunctionforthelifeoftheproject.However,thisright-of-waymayinfluencelandusepatternsthat,likevegetationpatterns,willlingerafterthetermoftheactualtransmissionline.Theright-of-waymayassumethefunctionofatransportationroute;thistransport-ationroutemayeventuallyhavemoreimpactthantheoriginaltransmissionlineandevenoutlivetheline.Otherrights-of-waymayberoutedadjacenttothetransmissionline,thussettingaregionalpatternofcorridorsthatagainmayoutlivethelifetimesoftheoriginalutilities.Atransmissionlinewhichpresentlypioneersaright-of-wayintoundevel-opedareasmayimprintapattern,whichalthoughitmightshiftandfluctuatesomewhat,willdeterminefuturelanduseandtransportationandtransmissionnetworksforthatareafarbeyonditsownlifetime.Thiseffectissimilarforotherrights-of-waywhichpioneerlargeundevelopedareas.AgoodexampleofthisistheAlaskaRailroad,whichisnowparalleledbydistributionandtransmissionlinesandahighway,andwhichresultedinthecreationofseveralsmallcommunitiesalongitslength.92 Anothereffectonthelong-termproductivityoftheareabythetransmissioncorridorwouldspringfromtheinterconnectionoftheelectricpowergridsofthetwolargestpopulationcentersintheState.Interconnectionwouldenableuseofthecheapestgenerationandthemaintenanceofsmallerreservecapacity,whileatthesametimeresultingingreaterreliabilityforbothsystems.InterconnectionwouldassumeanimportancenearlyasgreatasthefunctionofdeliveryofUpperSusitnapower.NewpopulationcentersarisingintheRailbeltareawouldbeaidedbyproximitytothisinterconnectedsystem.Thegrowthofenergy-intensiveheavyindustryalongthecorridorduetotheavailabilityofpowerispresentlyunlikely;thisisduetothehightransportationandlaborcostsofthearea,whichwouldoutweighttheadvantageoftheavailabilityofrelativelycheappower.TheconstructionofaninterconnectedpowersystemfortheRailbeltisaresponsetotheincreaseddemandforelectricpower.Initself,theavailabilityofpowerisnotenoughtoinducegrowthofanarea:otherfactors,someofwhichareintra-andinter-regionaltransportation,theavailabilityoflabor,theexistenceofamarketformanufacturedgoods,produce,and/orrawmaterials,mustexistalsotospurregionalgrowth.Theseotherfactorsareprobablymoreresponsibleforgrowththantheavailabilityofpower.TherearenoimportantpotentialhydropowersitesalongthealternativecorridorsexcepttheWoodCanyonsite.Theviabilityofthisprojectme:'beenhancedbytheexistenceofthetransmissionroutewhichfollowstheRichardsonHighwayroute.However,otherfactorssucha.;largesizeofthepotentialprojectandenvironmentalimpactsoftheWoodCanyonprojectreducetheprobabilityofthisprojectbeingspurredonbytheprobabilityofanalternativecorridor.93 IRREVERSIBLEANDIRRETRIEVABLECOMMITMENTSOFRESOURCESThematerialsdirectlyusedintheconstructionofthetransmissionlineandaccessroadswillbeirretrievablycommittedforthelifeofthetransmissionline.Thesematerialsincludethealuminumandsteelinthetowers,aluminumandsteelinthecablesandguys,insulators,steelculverts,gravelandconcrete.Ofthese,aluminumandsteelhavescrapvalueandcanberecycled.Maintenancevehicleswillbeirretrievablycommitted,sincetheirresalevalueafterfullusecanbeexpectedtobelow.Thefuelexpendedonconstructionandmaintenanceisirretrievablycommitted,asareotherchemicals,suchaspaint,ifsteeltowersaretobecoated,andherbicides,ifchemicalcontrolofvegetationisused.Thelandoccupiedbytheright-of-wayisirreversiblycommittedforthelifeoftheproject,althoughitemreverttoitsoriginaluseorsomeotheruseafterretirementoftheline.Thislandcan,forthemostpartbeusedforotheractivities,suchasrecreation,access,oragriculture.Thisis,however,atthediscretionofthelandownerorland-managingagency.Landusepatternsmaybepermanentlyaffectedbythepatternoriginatedbythetransmissioncorridor,witheffectsoutlivingtheoriginaltransmissionline.Irreversibleecologicalchangesmayresult,dependingupontheamountof'earingorlarge-scalechangeimposeduponanareabyaright-of-way.Mostofthesechanges,suchasthemaintenanceofsuccessionalvegetationinanotherwiseclimaticforest,willeventuallyreverttotheiroriginalcondition,afterretirementofthetransmissionline,althoughthismaytakeaconsiderableperiodoftime.Mineralextractionmaybeaffectedbythelocationofthetransmissionline;sucheffectsprobablywilllastforthelifetimeoftheline,unlessthelineislaterre-routedaroundorebodies.Thiswouldnotbepracticalforlowunit-valueminerals,suchassandandgravel.Inadvertantdisruptionofundetectedarcheologicalsiteswouldresultinirreversibledamagetosuchsites,reducingtheamountofinformationobtainableandtheirhistoricalorarcheologicalvalue.Discoveryofunharmedsitesduringconstructionwillbeabeneficialeffect,however.Thelaborspentinconstruction,operation,andmaintenanceofthetransmissionlineisirreversiblycommitted,asarethesecondaryeffectsoftheincreasedemploymentafforded.95 MATERIALSANDLANDCOMMITTEDConduc-jStruc-Lengthtors.!.turesYROW~jClearing'ifCorridor:SystemmilesTonTonacresacresSusitna-l:345-kv-DC1364,62413,6682,3082,308Susitna-l:230-kv-DC1363,5097,3442,0602,060Susitna-2:345-kv-DC1404,76014,0702,3762,376Susitna-2:230-kv-DC1403,6127,5602,1212,121Susitna-3:345-kv-DC1344,55613,4672,2741,900Susitna-3:230-kv-DC1343,4577,2362,0301,697Susitna-4:345-kv-DC1495,06614,9752,5292,257Susitna-4:230-kv-DC1493,8448,0462,2572,015Nenana-I:230-kv-SC1982,2546,1383,0001,439Nenana-I:230-kv-DC1985,10810,6923,0001,439Nenana-2:230-kv-SC2202,8386,8203,3331,500Nenana-2:230-kv-DC2205,67611,8803,3331,500Nenana-3:230-kv-SC2312,9807,1613,4501,318Nenana-3:230-kv-DC2312,96012,4743,4501,318Nenana-4:230-kv-SC2232,8766,9133,3781,182Nenana-4:230-kv-DC2235,75312,0423,3781,182Nenana-5:230-kv-SC2122,7356,5723,2121,364Nenana-5:230-kv-DC2125,47011,4483,2121,364Mata".ska-l:345-kv-DC2659,01026,6334,4972,817Ma+,,-uska-l:230-kv-DC2656,83714,3104,0152,515Matanuska-2:345-kv-DC38413,05638,5926,5163,869Matanuska-2:230-kv-DC3849,90720,7365,8183,454Delta:230-kv-DC2807,22415,1204,2421,727Delta:230-kv-SC2803,6128,6804,2421,727yAssumesterrain.YAssumesterrain.yAssumes'ifAssumesRailandPheasantconductorscanbe10%greaterinroughsteelfree-standingtowerscanbe10%greaterinroughR.O.W.widthof140'for345kv,and125'for230kv.totalclearingforfullwidthofright-of-way.DC=DoubleCircuit;SC=SingleCircuit.96 OTHERALTERNATIVESTOTHEPROPOSEDACTIONAlternativecorridorshavealreadybeendiscussedandcomparedontheprevioussectionsandonthematrixesintheappendix.Inthissection,alternativestobasicassumptionsoftheproposedtransmissionlinewillbediscussedalongwiththealternativeofnon-construction.SharingofRights-of-WayTheassumptionismadeintheproposedandthealternativecorridorsthatanentirelynewright-of-waywillneedtobeobtainedfortheentirecorridor.Sharingright-of-waywithanotherutility(notnecessarilyelectrical)mayobviatemanypotentialimpactsinthataccessmayalreadyexist,reducingconstructionactivitysomewhat,andthatpioneeringofnewcorridors,withattendantproblems,isnolongernecessary.Theproposedtransmissioncorridorcouldadjoinorsharetherights-of-wayoffivetypesofsystems:otherelectricaltransmission,communica-tio,",pipelines,railroads,andhighways.Althoughthebenefitineachcaseisasavingsintotallanduse,theadverseimpactsuponthesefivesystemsvary.Electvicaltransmissionsystemsthatarejointlyusingoneright-of-waywillsufferareductioninreliability,inthatacatastropheaffectingcneline,suchasseismicactivity,isverylikelytoaffecttheother.Safetyduringmaintenancewilldecreasesomewhat.Joi.'useofanexistingcommuniciationright-of-waywillentailpossibledemagetotheexistingsystemduringconstructionofthetransmission..e.Steadystatenoisemaybeinducedintothecommunicationline;thecommunicationlinewillalsobemorevulnerabletofaultandlightningdamage.Inthecaseofburiedcommunicationcables,errosionwilloccurunlesscorrectivemeasuresareused.Pipelinesaresubjectedtocorrosionriskalso.Thehazardsofconstructiondamage,shockandfiresorexplosionwillexist.Railroadswillbesubjectedtoshockandfirehazards.Communicationsmaysufferinterference,andinthecaseofelectricsignals,inducedcurrentmaycausefalsecontrolsignals.Alonghighways,transmissionlinescancontributetoradioandaudiblenoise,andinthecaseofaccidents,cancauseafireandshockhazard.Inthecaseofjointuseofrailroadandhighwayrights-of-way,theriskofaccid~ntsonthesesystemsaffectingtheintegrityofthetransmissionsystemmustalsobeconsidered.98 ]JTheaboverisksareconsideredwithnocompensationormitigation.Forinstance,corrosionofcablescanbecontrolled,ascaninducedcurrents.Properconstructiontechniqueswillgreatlyminimizeriskofdamage.Effectssuchasaudiblenoiseandresultingrisksoffireandexplosionfromaccidentscannotberesolvedwithjointright-of-wayuse.However,theuseofabufferstripbetweenright-of-waywillnotentailasavingsinland;inthecaseofadjoiningorpartialoverlapofrights-of-waysrequiringclearingthroughforest,theuseofabufferofstandingtreeswillrealizenosavingsinclearing.Notallrights-of-waysarevisuallycompatible;forinstance,sharingofright-of-waywithamajorhighwayortrailsystemswillcauseanunacceptablescenicimpact.Forhighways.thisincompatibilitymustbeweighedagainsttheadditionalscenicvisualirnpactofviewLngtheparallel,butseparaterights-of-way.However,utilitiesnotdirectlyinvolvinghumantransportationorthoseincommercialorindustrialsurroundingsaresuitedforright-of-waysharingparticularlyiftheutilityisanexistingtransmission,one.OntheproposedcorridortoFairbanks,theGoldenValleyElectricAssociationownsa138kvtransmissionlinefromHealytoEster.Itispossibletocombinethislinewiththeproposed230kvdouble-circuitlinefromDevilCanyor.byupgradingtheproposedlineto345kvdouble-circuitandadc1;ngenoughwidthtomakea140footwideright-of-way.Thiswouldbeamoreefficientuseoftheland,alongwiththeeliminationofredundancyofparalleltransmissionlines.Anotherexistingright-of-waywhichcouldbesharedisthatofthe."lyeskaPipeline.Thisisaright-of-waywithanexistingroadfornearlyitsentirelength;useofthisutilitywould,however,entailalongertransmissionline.Thepumpingstationsalongthepipelineareplannedtooperatewithaportionofthetransportedoil;however,ifthestationsweretobeelectricallyoperated,theycoulddrawpowerfromanadjacentdistributionlinewhichtapsthetransmissionline.Extrawidthwillneedtobeobtainedfortheright-of-wayifthetransmissionlineweretofollowthepipeline.Thefeasibilityofhavingindividualtapstoservethepumpingstationsislow,duetotheinordinateexpenseinvolved.Oneutilityright-of-waycloselyfollowstheproposedtransmissioncorridorfornearlyitsentirelength.ThisistheAlaskaRailroad,ownedbytheFederalGovernmentandoperatedbytheDepartmentofTransportation.99 Insomecases,theuseofundergroundtransmissioncanbejustifiedtoreducevisualimpactswheretheseimpactsarejudgedtobegreaterthantheadverseimpactsofundergrounding.Suchasituationistypicalinthosehighlyscenicareaswherethetransmissionstructureswouldeitherbesilhouetted,highlyvisible,orhighlyobtrusive,yetwheretheaccessroadandtrenchingscarofanundergroundcablewouldnotbeoverlyvisible.Thissortofsituationwillruleoutcanyonsandotherhigh-reliefareas,butwillfavorrelativelyflatland.Thegreatestvisualdifferencebetweenundergroundandoverheadtransmissionisobviouslythelackofthetransmissionstructures.However,anundergroundsysteminallcaseswillrequirenotonlyanaccessandconstructionroad,butalsoatrenchwhichwillbevisibleforquitesometimeafterconstruction.Overheadsystems,however,canbebuiltwithouttheneedforanaccessorconstructionroad,andtheonlyexcavationneededwillbeforthetowerfoundationsspacedoutatarateoffourorfivetoamile.Ii,helocation,design,andconstructionofanoverheadsystemareproperlyspecified,theaccessroadandclearingwillbeasvisible,andusuallymorevisible,thanthestructuresthemselves.Whereclearingisnotneeded,the;Gostvisiblecomponentwillthenbetheaccessroad,andasindicated.eventhisneednotbeconstructedforanoverheadsystem.Incontrast,anundergroundsystemwillalwaysneedaclearinginanyareaandwillalwaysneedaconstructionroad.Thus,anundergroundsysteminrollingorsteepterrainmaywellL,"lOrevisiblethananoverheadsysteminthesesituations.Fortl°1Sreason,coupledwiththeseismicrisktobediscussedbelow,.'snotrecommendedthatthesectionofcorridorthroughtheAlaskaRangebeunderground.Amajorfactorintheuseofundergroundsystemsisthecost.Transmissionsystemsareusuallydesignedtomeetgivenrequirementsfortheleastcost;inalmostallsituations,overheadlineswillmeetsystemrequirementsatalowercostthanundergroundcables.TheA.D.LittleReporttotheElectricResearchCouncil(October1971)statesthatundergroundtransmissioncostscanbeashighastentimesgreaterthanoverheadsystems,andinthecaseofcompressedgascablesystems,upto20times.Undergroundsystemsgenerallyinvolvehighermaterialscostforthecableandforassociatedmaterialssuchasinsulatingbackfillorprotectivesheeting.Installationismorecomplicated,involvingexcava-tionandbackfillingandlaboruseishigherthanforoverheadsystems.Splicingofd365kvcablecantakeeightormorefullworkdaysandmustbeperformedinspeciallyconstructedair-conditionedrooms,("UndergroundPowerTransmission",P.H.Rose,Science,Vol.170,Oct.1970).101 Theoretically,overheadsystemshavemoreoutagesthanundergroundsystemssincetheyareexposedtoweather,vandalism,andaccidents;however,unlessdamageisexceptionallysevere,includingfailureofoneormoretowers,oraccessisrestrictedbyweather,theseoutagesareofshortduration.Faultsinundergroundcablesmayresultinlong-termoutagesuptoseveralweeks;thisresultsfromthedifficultyinlocationofthefault.thetimeinvolvedinexcavationandbackfilling,andthetimeneededtoreplacethefaultedsectionbysplicinginanewsection.Inseismicallyactiveareas,suchascanbefoundintherailbelt,thereliabilityofundergroundcablesmustbequestioned.Slicingofthecablecanresultfromsettlingorslumpingofthesoil;oil-filledorcompress-gasfilledcablesmayruptureduringsoilmovement.Otheragentscancausefaulting,suchasrodents,corrosion,andsubsequentexcavation.Locationandcorrectionoffaultsinacablefollowingquakesmayinvolveconsiderabletimeandeffortasopposedtcthelocationoffaultsinanover]"dsystem.Overheadtransmissionlineshavemoreinherentresiliencythanundergroundcables,andfaultsaremoreaccessibleandeasiertolocate.Environmentalimpactsofanur1d"rgroundcablecanbequitesignificantinthatacontinuoustrer,chiorequiredandanaccessroadismandatoryfortheconstructionvehiclesandthelayingofthecable.ThebackfilledtrenchmaycaUSeerosionalproblems.particularlyifthetrenchcutsupordownslopes.Aclearedright-of-waymustbeprovidedformaLtenancevehiclesneededtounearthafaultedline;however,3clearingneednotbeaswideasforanoverheadsystem.RepairswiI)involvere-excavation.withattendantimpactsduetopotentialerosion.Anundergroundcableinusewillcontinuouslygiveoffheat;thiscanbeveryseriousinice-richpermafrostareas,whichoccurinallofthealternativecorridors.Insulatingbackfillwillretardbutnoteliminatethisheatflow;heat-transferdeviceswillbenecessarytopreventexcessiveslumpingandsettlingofice-richareastraversedbyanundergroundcable.Generatedheatwillalsoaffectthegrowthofvegetation,butthisdoesnotappeartobeasignificantimpact.Duetotheexpenseanddifficultyofinstallation,undergroundcablesareratherinflexiblewithregardstochangingpowerneeds.Theadditionofanothercircuitortheadditionoftapsforlocalcommunitiesisverydifficultincomparisontooverheadsystems,wheretheadditionofanadditionalcircuitwillnotrequireanotherright-of-way,andtheadditionofatapwillnotinvolvetheexcavationofthecable,splicing,andterminalfacilitiesfortheoilorpressurizedgasinsulation. Onhillyterrain,unreinforcedlow-pressure,oil-filledcableissubjecttopossibleruptureduetotheincreasedoilpressureatthelowpointsofcables.Reinforcingandpressurecompensationdevicesarenecessaryinthistypeofcableoverhillyground.High-pressureoil-filledpipecablerequiresacontinuoushighpressuremaintainedbypumps.Thistypeofundergroundsystemisalsosubjecttopressuredifferentialsduetoelevationchanges.CablesfilledwithnitrogenorSF6gascontainconductorswrappedwithoil-impregnatedpaper;onhillyterrain,thisoilwillseeptothelowerends,andsothiscableisonlysuitedforlevelterrain.Cablesinsulatedwithsolidinsulation,suchascross-linkedpolyethylenearesubjecttomanufacturingflaws,suchassmallvoids,whichcanlaterdevelopintoelectricalfaults;theprobabilityoffaultsisproportionaltothevoltage.Usageisusuallylin,itre!to138kvorlower.Amajordisadvantageofundergroundsystemsisthecarryingcapacitydictatedbycapacitivereactance.Capacitivereactanceisinherentinthecableconstruction,andreS'.iltsinachargingcurrentwhichdecreasestheusablepowerthatcanbetransmitted.Thepowerlossinanundergroundcableis25to30timesgreat~rthanforanoverheadsystem.Ifacableexceedsacertainlength,itstransmissioncapacitybecomeszero.Foracableof115kv,thislengthisabout45miles;fora230kvcablethelenpt11isabout35miles.Inotherwords,fora230kvcable35mileslong,th.·,ossisequaltotheinputpower.ToJvercomecapacitivereactancelosses,andthuslengthenthecriticallengthofanundergroundcable,shuntreactorsmustbeinstalledatperiodicintervalsalongthecable.Theseshuntreactorsarepreferrablylocatedabovegroundforaccessandheatdissipation,andarebasicallyequivalenttoaseriesofminiaturesubstationswiththeattendantsimilarenvironmentalimpacts,highreductioninreliability,andaddtionalcosts.ResearchtoimprovetheundergroundtransmissiontechnologyiscarriedonbytheDepartmentoftheInteriorthroughtheOfficeoftheAssistantSecretaryforEnergyandMinerals,andbyprivateindustrythroughtheElectricPowerResearchInstitute;privateindustryismakingbyfarthegreatercont-.cibution,spending$14millionduringfiscalyear1974ineffortstoadvanceundergroundtransmissiontechnology.OneresultofrecenteffortsistheCompressedGasInsulatedBus(CGIB).Althoughstill10to20timesmoreexpensivethanoverheadtrans-missionandofuntestedreliability,thissytemcanhandle500kvwithacriticallengthofupto200miles,atenfoldimprovementoverprevious103 criticallengthsforthisvoltage.Thepotentialadvantagesofsuchasystemincludereducedvisualimpact,noaudiblenoiseaselectro-magneticinterference,smallvolume,simplicityofmaintenance,andpowerhandlingcapabilityapproachingthatforoverheadsystems.BonnevillePowerAdministrationplanstooperatealengthofprototype500kvCGIBnearEllensburg,Washingtonstartingthesummerof1974toaccumulateexperiencewiththissystem.Eventually,undergroundcablesmaybeexpectedtoequaloverheadsystemsinperformanceandoverallreliability;however,sincemostofthecostofanundergroundsystemisattributabletolabor,thecostdifferentialbetweenthetwosystemsisnotexpectedtodecreasesignificantly.DirectCurrentTransmissionDirectcurrenttransmissionhasbeenusedinseveralcountriesforbulktransmissionofpoweroverlongdistances.Duetothehighercostsofconversion,thistypeoftr'msmissionisusuallyusedfordistances01500to1,000milesbetweenconverterstations.IfnoitermediatetapsareplannedbetweenthegenerationsiteandAnchorageandFairbanks,thenthe136mileand198milE'lengthsoftheproposedcorridorsareconsiderablyshorterthantheeconomicaldistances.Intermediatetapstoservepresentlyuncor.ilectedtownandfuturepopulationcentersalongthesecorridorswOll1drequireconverterstationsandevenshortertransmissionlengths.>::,lronmentalimpactsofd-ctransmissionsystemsaregenerallythe~omeasfora-csystems,exceptthatd-csystemsrequireonlytwoconductorsinsteadofthree,andthuswouldrequireaslightlynarrowerright-of-way.Forundergroundtransmission,theuseofdirectcurrentwillobviatelossesfromcapacitivereactance,andinthisway.enhancetheviabilityofundergroundingwhileimposingtheadditionalcostsofconvertersateachendofthecable.Theuseofd-cinundergroundsystemswillnotlowertheinstalledcostpercable,norwillitenhancereliability.Theneedforonlytwocableswilllowerthetotalcostversusa-ctransmission,andifonecableisfaulted,theothercanfunctionathalf-capacitywithpropergrounding.Thelimitationsofd-ctransmissionpresentlyaregreatenoughsothatitcannotberecommendedfortheUpperSusitnaRiverProject.However,technologicaladvancesmayeventuallyprovideacheaperalternativetothepresentconverters,andthusprovidetheflexibilitypossessedbythea-csystem.104 AlternativeSystemPlansTheproposedsystemplanspecifiesa345kvdoublecircuitlinefromthegenerationsitetoAnchorageanda230kvdoublecircuitlinefromthegenerationsitetoFairbanks.The"TransmissionReport"discussesanalternativesystemplanwitha230kvdoublecircuitlinetoAnchorageanda230kvsinglecircuitlinetoFairbanks.Fordesigndetails,refertothe"TransmissionReport".Theenvironmentalimpactsofthisalternativesystemplanwillbeessentiallyidenticaltotheproposedone.Therewillbesomemajordifferences,however,intheamountofright-of-wayandclearingforallthealternativecorridorsfromthegenerationsitetoAnchorage,andintheamountsofmaterialscommittedforallthealternativecorridors.Thesedifferencesarereflectedinthetableonpage88.Theright-of-waywidthfor230kvis125feet;for345kvitis140fed.Doubleandsinglecircuitline..,ofthesamevoltagerequireidenti-calwidths.Thestructuresneededfor345kvareslightlylargerthanthosefor230kv,andinsomecases,maybemorevisible,butthisisunlikely.AnotheralternativeistheconstructionoftransmissionlinesalongtheMatanuska-lor-2andtheDeltacorridorsinconjunctionwiththeproposedsystem.Thesecorridorswouldnotnecessarilybeconstruc-ter1'Itthesametimenorsamevoltagesorcapacitiesastheproposedsvs,em.Themainadvantageofsuchasystemwouldbetheincreasediabilityofredundantlines,andtheinterconnectionofcommunitiesalengtheGlennandRichardsonHighways,theCopperValleyElectricAssociationandtheinterconnectedsystemproducedbytheproposedsystemplan.TheenvironmentalimpactsoftheseadditionalcorridorswouldessentiallybethesameasthoseoutlinedforMatanuska-land- 2andtheDeltacorridors.However,theamountsofright-of-way,clearing,andmaterialscommittedwilldependuponthevoltageandcapacitiesoftheseadditionalcorridors.Fordetails,refertothe"TransmissionReport".AlternativeMethodsofConstructionandMaintenanceAccessRoadsversusHelicopterConstruction:ItisproposedtobuildpermanentaccessroadsforthelengthofboththeproposedSusitna-landNenana-lcorridorswiththeexceptionofone--fromGoldCreektoHealy.TLisareawillbeconstructedbyhelicopteraccess.105 Theadvantagesofanaccessroadoverhelicopteraccessare:lessexpensivepermileovermostterrain;easeintransportationofmachineryandmaterials,towererection,strengthofconductors,andremovalofmerchantabletimber;morereliabilityofaccessformaintenanceandinspection;andmultiple-useofcorridor.Disadvantagesofanaccessroadare:increasedmaintenanceproblems;unauthorizeduseofaccessroad;potentialincreaseinerosionandsiltation;andincreasedvisibility,moreclearingrequiredwithsubsequentimpacts.Sinceneitheralternativemethodissuitablefortheentirelengthoftheproposedcorridor,theproposedmethodofaccessisthatwhichwasjudgedtobemostsuitabletothelocation.WinterAccessversusYear-RoundAccess:Transportationofmaterialsandmachineryandconstructiond"ringwinterwouldeliminatemanyin'l,actsrelatedtoaccessroadcon~lructionandtowererection.Withtotalwinterconstruction,theaccessroadwouldnotbenecessary.Disadvantagesofwinteraccc·ssandconstructionare:theconstructionseasonwouldberatherlimlted:conditionswillbeharshonmenandmachinery;snowandfroze"groundmayinterferewithexcavationandplacementoftowerfootings;thelackofanaCcessroadwillaffectthereliabilityofmaintenanceaccess,andwillelimiateanymultiple-us~oftheclearing.·jmsideringthesiteofthisproject,itisnecessarytouseasmuchoftheyearaspossibleinordertocompleteconstructionwithinareasonabletime.Also,givensomeoftheweatherconditionsandthelengthofthecorridors,reliabilityofacceSSisimperative,especiallysincethereisnoproposedback-uptransmissionlineincaseofafault.Thus,wheneverpossible,year-roundconstructionwillbeused.Asoutlinedabove,accessroadswillbeusedwheneverindicated.AlternativeMethodsofClearing:Presently,someoftheclearingmethodsusedbytheutilitiesareassimpleasbulldozingoveranyandalltreeswithinasetdistancefromthecenterlineoftheright-of-way,insuringenoughwidthforanaccessroad,easeofconstruction,andclearancebetweenfallingtreesandtheconductors.Thismethodisfairlydirect,involvinglittlediscretionbetweenwhatiscleared,andactuallywhatisminimallynecessaryforconstructionandmaintenance.However,thismethodalsoresultsinexcessivedisturbanceofthesoilandunn"cessarydestructionofvegetation.106 Considerablycheaperandlessenvironmentallydamaging,thetechniqueofonlyclearingthatvegetationnecessaryforconstructionandmaintenanceisrecommended.Insteadoftopplingtreeswithabulldozer,selectivecuttingisused,allowingstumpstoremain.Therearethreemethodsofdisposalofclearedvegetation:salesofmerchantabletimber,burning,orchipping.Allthreealternativemethodswillbeusedwhereapplicable.Saleoftimberwillrequireanaccessroad;someofthetimbercanbeusedinroadconstructionintimberbridgesandcorduroyinmuskeg.Alsointhiscategoryistheofferingoftimbertoanywhowishtoremoveitforfirewood;thiswillonlybesignificantnearsettledareas,andanytimbernotdisposedofinthiswayafterafewmonthswillbedisposedofinotherways.Ifnoaccessroadistobeused,thenopenburningistheonlyavailablen,'thodofdisposal.Atemporarydeclineinairqualityisinevitable,andopenburning,inanycase,willbesubjecttolocalordinancesoftheaffectedboroughs.Forced-draftburningwillconSIderablyreduceparticulates,butwillrequireanaccessroadfortl-,elargetubburners.Inanycasewhereburningisallowable,whereanaccessroadwillbebuilt,andwherechippingisnotnecessary,forced-draftburningwillbeused.Ina.'easwherelarge-scaleburningisprohibited,orwherechippingis'esuitable,thenslashandunsalabletimberwillbechipped.AI1lOughmostexpensiveandtimeconsumingofthethreemethods,chippinginmanyinstancesispreferable.Wherepermafrostdegradationislikely,wherethesurfacematofvegetationhasbeenseriouslydisturbedordestroyed,oronpotentiallyerosivesoils,theuseofchipsasaprotectivehumusisindicated.Chipswillprovideameasureofinsulationoverice-richfrozensoils,someprotectionforbaresoils,andalthoughdecompositionratesareslow,anorganicmulchtoaidrevegetation.Sincethechipswilllieontheground,andusuallybesomewhatwet,theywillpresentlessofafirehazardthanunchippedslash.Afourthmethodofdisposalistostackslashandallowittonaturallydecompose.Althoughthiswillprovideatemporaryhabitatforsmallmammals,itwillalsoprovidegoodhabitatfordestructiveinsects,providefuelforfires,andreducethevalueoftheclearingasafirebreak.Thus,thiso;)!ionisnotrecommended.107 AlternativeMethodsofClearingMaintenance:Inareasoffastregrowth,someperiodicsuppressionoftallplantsisnecessary.Therearethreemajoralternativemethods:aerialapplicationofherbicide,manualapplicationofherbicide,andphysicalcuttingoftreesandbrush.Aerialsprayinginvolvesthecoverageoflargeareaswithherbicidessprayedfromanairplane,ormorefrequently.ahelicopter.Duetothenon-selectivenatureofapplicationandtheriskofaccidentaloverspraying,sprayingofwaterbodies,andimproperconcentrations,thismethodisnotrecommended.Manualapplicationofherbicidesinvolvesthesprayingoftargettrees,dispersalofpelletsatthebaseoftargettrees,orselectivesprayingofthicketofbrush.Itisrelativelysafefromtherisksassociatedwithaerialspraying,andalsomuchmoreselective.Itcanbecarriedoutduringroutinegroundinspectionsorduringscheduledprogramsofbrushsuppression.Physicalcuttinginvolvestheidentificationanddestructionofdangertreesandtheperiodicsupprp~sionofbrush.Chainsaws,brushaxes,andmotorizedrotaryaxepcanbeusedforthis.Thelaborexpendedisgreaterthanformanualav,Jiicationofherbicide.butissafeforuseadjacenttowaterbodies.Iflargeareasofbrusharecut.theslashmustbeburnedorchipped.Smallamountsofslashwidelydispersedwillnotposeaninsecthazard.~.erecommendedmethodofcontrolisthemanualapplicationofherbicidesWJ'hcuttinginsensitiveareas;aerialsprayingisnotproposed.AlternativeEndpointsForthisfeasibilitystudy,itwasnecessarytopostulatedefiniteendpointstoallowdeterminationcosts,clearing,etc.Thisinnowaywillfinallydefinetheendpointsoftheactualtransmission,justasthelocationofacorridordoesnotattempttolocatetheactualplacementofatransmissionlinewithinthatcorridor.ThechoiceofendpointsoftheNenanaandDeltaalternativecorridorsisrelativelylimitedtothosealreadypostulated--EsterandFairbanks.Unlessnewsubstationsweretobebuilt,thesearetheonlytwofeasiblechoices.However,fortheMatanuskaandSusitnaalternativecorridors,twoalternativeendpointsareobvious.PointMacKenzieistheterminusofasetofu,,-derwatercablestoAnchorage;PalmeristhenorthernendofanexistingAPAtransmissionline.108 PointMacKenzieisfarclosertothemainloadcenteratAnchoragethanPalmer;thetransmissioncorridorwillcrossrelativelylessdevelopedlandtoapproachAnchorageviaPointMacKenziethanviaPalmer.PowerwouldbemarketeddirectlytoChugachElectricAssociation,andwheeledovertheirsystemtoAnchorageMunicipalLightandPower,HomerElectricAssociation,MatanuskaElectricAssociation,andtheSewardElectricSystem.DeliverytotheexistingAPAsystematPalmerwouldavoidthelimitationsandriskofthesubmarinecrossingofKnikArm,butwouldinvolvemorecrossingofprivatelyownedland.PowerwouldbemarketeddirectlytoAnchorageMunicipalLightandPowerandChugachElectricAssociation.PowerwouldbewheeledovertheCEAsystemtoHEA,SES,andMEA.TheenvironmentalassessmentfortheSusitnacorridorwithanendpointatPalmerwouldbesubstantial1ythesameasthatfortheproposed,-:stem.Mileage,clearing,andoL,erimpactswouldremainvirtuallythesame.IfthecorridorweretoberoutedalongtheuplandsnorthoftheAnchorage-FairbanksHighway,somewhatbettersoilswouldbeencountered,andmorep,ivatelyownedlandandfarmswouldbecrossed.FortheMatanuskaalternativecorridors,therewouldbemoresubstantivedifferences:thecorridorwouldbeabout45milesshorter,andwouldinvolveupto764acreslessofright-of-wayandclearing.Also,l,e,materialswouldbeused,andlesslaborexpendedbyutilizingePalmerendpoint.APAwillcontinuetoproposethePointMacKenzieendpointuntilmoreinputfavorabletotheutilizationofthePalmerendpointisreceived.NoAction(Nonconstruction)Indiscussingthealternativeofnon-constructionoftheproposedtrans-missionline,theviabilityoftheUpperSusitnahydroelectricprojectmustbeconsidered,sincetheprimarypurposeofthetransmissionlinewillbetodeliverthegeneratedpowertothemajorcentersintheRail-belt.Inessence,non-constructionofthetransmissionlineimpliesnon-constructionoftheUpperSusitnapowersites.NoactionwillmeanthatthepotentialpoweroftheUpperSusitnawillnotbemadeavailabletotheRailbeltarea.Sinceuseofpowerisprojectedtoincrease,alternatesourcesofpowerwillhavetobeused.Ifpresentplantsareupgraded,thiswillresultintheincreaseduseoffossilfuelssuchascoalandgas.Itisnotlikelythatcostsoffossilfuelswillremain109 thesame,andtheywillalmostcertainlynotdecrease.Developmentoflarge-scalehydroprojectswillprobablybebeyondthecapabilityofthepresentutilities,sofossilfuelswillbeusedforarelativelylow-priorityusewhereasarenewableresource,waterpower,willgountapped.Ifadditionalpowersitesarerequiredtosatisfyenergyneeds,astheyprobablywillbe,thentheywillrequiretheirowntransmissionsystemstodelivertheirpower.Thus,non-developmentoftheUpperSusitnaanditstransmissionsystemwillnothaltfurtherconstructionoftransmissionsystemsbyotheragenciesorutilities,andifnewpowersitestendtobesmall-scaleduetoinabilityofutilitiestodeveloplargehydrosites,thenmoretransmissionlinesmayresultthaniftheUpperSusitnaweretobedeveloped.Anothereffectofnon-constructionwillbetopreservetheinsularanddisconnectedcharacteroftheutilitysystemspresentlyservingtheRailbelt.Atransmissionlinetobe"uiltwiththemainpurposeofinter-connectionwouldnotbelikelyinthenearfuture,andtheduplicationandwasteofthepresentsituationwillbeprolonged.110 thesame,andtheywillalmostcertainlynotdecrease.Developmentoflarge-scalehydroprojectswillprobablybebeyondthecapabilityofthepresentutilities,sofossilfuelswillbeusedforarelativelylow-priorityusewhereasarenewableresource,waterpower,willgountapped.Ifadditionalpowersitesarerequiredtosatisfyenergyneeds,astheyprobablywillbe,then theywillrequiretheirowntransmissionsystemstodelivertheirpower.Thus,non-developmentoftheUpperSusitnaanditstransmissionsystemwillnothaltfurtherconstructionoftransmissionsystemsbyotheragenciesorutilities,andifnewpowersitestendtobesmall-scaleduetoinabilityofutilitiestodeveloplargehydrosites,thenmoretransmissionlinesmayresultthaniftheUpperSusitnaweretobedeveloped.Anothereffectofnon-constructionwillbetopreservetheinsularanddisconnectedcharacteroftheutilitysystemspresentlyservingtheRailbelt.Atransmissionlinetobe')uiltwiththemainpurposeofinter-connectionwouldnotbelikelyinthenearfuture,andtheduplicationandwasteofthepresentsituationwillbeprolonged.no ACKNOWLEDGEMENTSInthepreparationofthisdraftenvironmentalassessment,AlaskaPowerAdministrationhasworkedinclosecoordinationwiththeAlaskaDistrictCorpsofEngineers.Inaddition,APAhasreceivedvaluableassistancefromtheBonnevillePowerAdministration,particularlyintheselectionofalternativecorridors.FurtherassistancehasbeengivenbytheBureauofLandManagement,theBureauofReclamation,theFishandWildlifeService,theNationalMarineFisheriesService,andtheNationalParkService.CommentsandadvicehavebeengivenbyvariousStateagencies,chieflytheAlaskaDepartmentofFishandGameandtheAlaskaDepartmentofHighways;alsotheUniversityofAlaskahelpedwithcommentsandadvice.112 AppendixIThefollowingappendixwilldiscussgeneralcharacteristicsofthephysicalandsocialcategoriesusedintheassessmentoftheproposedcorridorsandtheiralternatives.Bothadefinitionordescriptionofthecategoryandadescriptionofpotentialimpactsinthesecategoriesfromatransmissionlinecorridorwillbediscussed.Notethephase"potentialimpacts";notallimpactsdescribedwillnecessarilyoccur.Thissectionisintendedonlyforbackgroundinformation;specificandmoredetailedtreatmentoftheproposedcorridorsandtheiralternativesiscoveredunder"EnvironmentalAssessmentofCorridors"and"Assess-mentofImpacts".TopographyandGeologyThisisoneofthemoreimportantcategories,fortopographyinfluencesmostofthesucceedingones.1'01'",raphyisitselfasurfaceexpressionotunderlyinggeologyandtectonics(forconvenience,tectonicswillbeconsideredundergeologywhilehydrologywillbecoveredalongwithtopography).TheRailbeltareaischaraet('_lzedbythreelowlandareasseparatedbythreemajormountain:.reas.TothenorthistheTanana-KusldkwimLowland,whichisdelineatedbytheAlaskaRangetothesouth.TheSusitnaLowlandistothesouthwest,boundedtothenorthbytheAlaskaP,e,andtotheeastbytheTalkeetnaandChugachMountains.Theropel'RiverLowlandintheeastisboundedonthenorthbytheAlaska'"mge,andthewestbytheTalkeetnaMountains.Eachbasinisunderlainbyquaternaryrockssurfacedwithglacialdebris,alluvium,andeoliandeposits.ThemountainsareprimarilymetamorphicandsedimentaryrocksoftheMesozoic,withseveralareasofintrusivegraniticrocksintheTalkeetnaMountainsandtheAlaskaRange,andMesozoicvolcanicrocksintheTalkeetnaMountains.FigureIdelineatesthemajorfeatures.TheRailbeltisanactiveseismicarea;the1964earthquakewasperhapsoneofthemostdestructiveearthquakesonrecord.Theseismichistoryisshortrelativetothetimeoverwhichstrainsaccumulatetoproduceanearthquake,sohistoricseismicityisapoorguidetopotentialseismicrisks.ThereareseveralsignificantlyactivefaultsintheRailbeltarea.ThemostspectacularfaultintermsoflengthandprominenceistheDenaliFault,alongarcbisectingtheentireRailbeltthroughtheAlaskaRange.Maximumexpectableearthquakesintheareacanbeofatleas1amagnitudeof8.5ontheRichterScale.Figure2depictsseismichistoryoftherailbeltfrom1899to1964.I - 1 deposits, Paleozoic intrusive rocks;granitic and 111:h'~10"lfir Fault (Dashed where inferred) Paleozoic volcanic - IVlesozoic volcanic MESOZOIC shale; includes some metamorphic rocks Mesozoic intrusi ve PALEOZOIC AND PRECAMBRlAN Metamorphic rocks:schist,.; mainly Paleozoic PALEOZOIC AND PRECAMBRIAN Sandstone,shale,limestone; includes some early Mesozoic rocks Quaternary and IGNEOUS ROCKS Source:C.S.G.S. APA-1975 H I I\) SOURCE:u.s.c.aG.S.1966100MilesA.P.A.-JULY197550MENTOFTHEINTEIPOWERADMINISTRATIONKS:IMY'l.~_MAGNITUDE~6o1-3 theareaurJldE,l'con.siidera"tioni::Hli::LJeli::LRiver,therangeI - 4 summertomoist;andlowsoilpermeability,issoil!l!le:gralnmaterial,isverysusceptible!o:rlTlat:ionofice.I.el!::><;;;:,excessivemoistureateven1';<;;U'•.1.C;Sll:)pesthe.I..l..l..llH,::>insolationmorainalYn"t",V';fromloess,orwindareevidenttheAlaskaYn<nnvIltll1=,ac:tsofatransmissionwillasaofu,'t,,,,.c:andanyaccessroads.Constructionpo!tent:lalforsurfacematSrU1=lU,onofsurface,canresultTheexistenceandmaintenanceofanaccesscauseerosion,thoughtoalesserthanconstructionsurfacebyanonfinegrainsoils.couldresultlandoronsideslopes.I-6 causedco:ntJ~olproceduresmayP€:rnna:trc)standtheresultantsettlInganderosionmayIncreasedinsolationwherematdirect,orfromover-.Destructionofmayalsorltiva"".FireCO!lstantmainten;3.nc;eofis"'1'"rluarea.class-andriverCharacteristicbutislimitedtothellJ.~LJ'<::J.sp,eC:IesCODJpOSltlOnvariesdueto;:>J.i!JJ.Jld.Ltobottomlandspruce-1Polol;:ntreessnrl1ice:-hard;;voodisgenerally101l.1nd~"P'"'""Q,,,"dE'PC)S:LtS,outwashpoorersoilsorsites,,oronspruce, 3! toc:: '"Iro "'''"'';/L.V ON VEGETATIVE TYPES .." ~ Source:Joint Federal-State Land Use Pl;~nning Commission Wet Tundra APA -July 1975 Moist Tundra Alpine Tundra Low Brush,Mtlsl'~eg:-J:'og Low land Spru.ce-H.ardVl1ocld Coastal He:mlock Bottomland Sn,rt'l ('1"-F'mc'1:>1" Up land Snruce--H;u'clwIJod [::..:::.::'::.:,']:-.:<.:-:..:.'::<;.HIgh Brush......";',';- 1-95U.S.DEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONoA.P.A.-JULY1975 oLH'l,..oL',",-U.CO.:;>twosub-types.Oneexiststimberlineinmountainousareas,theotherexistsonactivefloodplainsofmajorrivers.areaspen,balsam,aldersandberries.onoutwashandoldandlowlands.alders,willows,andexistsonthe,andabovebe:cc>n<1a:ryeffectsofdeepen,lngoftheactivesuccessionalmaintainag1en1:scanbeincreasedinareas.Mosttherl11,.t=>,'T.ll,H..,a'~L'"ofatransmissionlineandaccessroaduponbecauseoftheratiooflandoc(;:ulneahn,,·,,'n,'upits,etc.tosurroundingunaffectedseCO,n(1a:ryimpactsareofgreaterconsequence.vege:ta'tlOn.Thisislimitedaht-,nt--'\xr:::>'\r.Primaryareasitwillprobablynh",n",,,cllm"j:la(:tisthelosstemporarily,thedecreased;inTn"l".,<::Tt=>rII -10 J.4,,-uaLc;.'u.regrowthandmaintenancealongtheright-of-wayareaareJ..I.<'/,;.U.j=;,l.I.,J.Cbeincreased.willresultinasUlb,::lim;axplantintorest,edareas;regrowthinanda:reaswillreach""-"LU""""asfarascon<1ltionsallow.Inanycase,directinprimarytheupontotaloftheIIweedIIspeciesI.,.",."riuadaptedtothetocom1=)et:enon-nativeorHowever,fewpJ."""'CC'notofthetundras,willareas.nativeSp1e(:le:sisapo'tentlalintowithincontamination.herbicidestocontrolinthephysicaldestruction.orS1=le(:lE~S--Sl:)eCln(:;isHerbicidescaneitherappl1C,:itloncanfromareproblemswithaerialapplication;applicationmoreselectiveandaccurate.Degenerationof!JJ.._J.....c;:,dE:p,~ndsonchemical,moisture,rateofbiodegradation.MostherbicidesusedinI -11 Nh+-,"+--n,-",controlareoflowtoxicitytoanimals,andappeartonon-cumulative,unlikemanypesticides.Contaminationoflakesandstreamsispotentialdestructionaquaticplantsmayfishhabitat.However,thisisoffsetthedecompositionanddilutionofherbicides.Thereislittleornoevidenceofaccumulationofonthesoil;leaching,action,andbyvegetationoftheperm'a1:l:'0~,te1:te<:tsinturnwillTJE~rlnaur·(]EiT.,suchasinV€:gl~tc,tiIJnthanmoreactiveisshallowalso.intheMatanuskaandTananaValleyshasshowntableduetotheoriginalandsubsequentvegetativemat,clearingororroadconstruction,willreducetheinsulationsummerwarmth.Theexposuredarkersoilwillthesecantoaltertheperma1:l:'os't-v'egeta,ticlnrlelatlOnSJtllpdestructionwillcauseerosionandthermc)k,ar:st;willalterwaterregiluethecover.,areinamoredelicateVE:gl~tc,tiIJncanalsocause::chan,gE:sinvegeta'tionecos'ystelusaredeep-changetheDf':rn1ajtrclstregllmeofanarea,Excessiveofandalsocanhavearesultmcdnta:ini.ngalowtodestructionofhabitatandcovertoenhancedhabitatConstructionandmaintenancetowhatrlpor'ppPote:ntjialman-causedcommunitiesseasonalofconstruction,andanu'llalclimaticvariation.Duringconstruction,potentialofman-caused,butdetectionshouldbe,andareasburnedandmaintenanceofthetransmissionline,m;:l.n'-C':l.used.firewillbelow,butdetectionslower,andconsequently,areasburnedwillbelarger.Operationoffire-fightingtheaccessroadsmaycauseconsiderabledamage.I -12 Variousplantcommunitiesdifferinrateoftocontrol:spreadandresistancetoControlUplandSn>:ru<ce-Har,dw'oodLowlandbD,rl:lCE~-tial'd'JVoodBottomlandSr,,,,,,,,',:>-IJ,.,,nlHighBrushTundrarUJ-'LUC;TundraHighMediumLowMediumMediumHighHighHighMediumLowpCftent:ia!existsUncontrolleduseman-causedril1lrlnothenpr;rlr'laccessroadswillincreasecapacl1:vof~=+Ic,"'+extremesinsumingofdeadplantfoodchain.ofthetaigaandtundrapopulationsorodluc:ti'vitvofthetaiga,Herbivore-basedfoodthetundra.an;mn,)}<'i':4Tlttundra.~diverseonl",t<,~r<",I<Hsmallofherbivoreso,eC:lesgenE~r<HltlE~ScandrawnThemostimportantt:'l('tn.}<'gov<er'ningandisthelow-n">";"",""andtheevenlowerp:t'oclul::ilchainsaremoredeV€'lo:pedInbothareas,aontheh,.nrl1"":4thesetlt:lctuaticmslowinthetundrachainLUetKI::::::;thisansensitivearea.Aonespecieswillhaveaninordinatesubsequentonotherinthefoodchain.Anthistenuousbalanceisinthefluctuationsinoftheseareperiodice:1i:pJ.OEaonslemmingandsnowshoeharepopulations,whicharerelatedtotheslightlylaggingfluctuationsof,suchDistributionofmoose,bear,Dahlsheep,caribou,areshowninFigures6,7,and8.ecosvstelmshavesimilarfeaturesoftheterrestrialecosystems."'l-'CI.,H;;::;'diversity,lowgrowthrates,andlonglifespansarecharac-teristicslakefish.Anadromousfishsuchassalmonareextremelyimportantintherailbeltarea;thelowerSusitna,Copper,andTananaRiversarethebasisforaconsiderablecommercial,subsistence,andsportfishery.1-13 U.S.DEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONLDIMOOSE,DALLSHEEp,BROWNBEARBrown/GrizzlyMooseCoI.centrotic:>nDollSheep/1-14o506100MilosA.P.A.-JULY1975 DEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONWILDLIFECARIBOUANDBISONMAP..'"~CaribouWinterRange~,,'::.~~~"".....",~Ca'"",~rlbouSummerRange;.::.'::.~'::.".."",.....~"","~CaribouCalvingRonge':'''?:''::.'''::.'''''~'''_~~1',~'~'~~'~'~~~1~IIIIIIII........,....._BisonRange,::.Source'JointFederal-StateLandUsePlanningCommissionA't-~"'"I-15aSCALE50IOOMilesA.P.A."JULY1975 Figure8100MilesA.P.A.-JULY1975SCALEo50WATERFOWLHABITATWILDLIFE.::::.::.::......···~.~..···.~·.·..8i..:..:·~m~~1~gl~1:~··..I··"'··/'~;:.4...~..'mln!!~~IIII.iU.S.DEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATtONI-16c?VICINITYMAP/1/Source'JointFederal-StateLaUsePlanningCommissionIl1lIlIlIIIHighDensityIlIIIIlllMediumDensityITIDlLowDensity Atransmissionlinepersewillnothavemanyimpactsuponwildlife;mostoftheimpactswillbeasaresultofconsu-uctionandmaintenance.Directdestructionwillaffectthelessmobileanimalssuchasthesmallmammals,whoseterritoriesmaybesmallenoughtobeencompassedbytheconstructionarea.Thesignificanceofthisimpactissmallinrelationtotheanimalpopulationinthesurroundingareas.Theconstructionareawillbereinvadedbyanimalsfromthesurroundingareaafterthelineisbuiltandregrowthproceeds.Huntingandtrappingbyconstructionworkerscanbeconsidereddirectdestruction;mortalityfromproject-relatedfirescanalsobeconsidereddirectdestruction.Amoreseriousimpactthandirectdestructionisthepreemptionofhabitat.Animalsforcedoutoftheirhabitatbyconstructionmaynotfindanotherniche;thisassumesthatthelandisatitscarrying·capacityforthatspecieswhichisaffected.Someanimals,suchascarnivores,willfleeatalmostallhumanintrusion;iftheyareforcedintoalower-gradearea,oraredislocatedforalongperiod,theywillbeweakenedandincreasedmortalitycanbeeXjoccted.Deliberateorinadvertantharassmentofwildlife,particularlylargemammals,willbeaseriousimpact.Flightstoconstructionsites,maintenanceflights,andoperationofvehiclesonopenareas,allhavethepotentialforanimalharassment.HarassmentduringcalvingforsheepandcariboucanC2.·<.Lseincreasedstillbirth.Althoughatransmissionandaccessroadwillnotimposeabarriertc.ligrationofcaribou,constructionworkduringcertainseasons,LYinhibitherdsfromapproachingworkareas.Thecreationofaclearedcorridorthroughheavyforestmayresultinincreasedanimalmovementalongtheright-of-way.Migratingbirdsmaysuffersomemortalityfromcollisionswithtowersorlines,buttheselossesshouldbenegligible.Thecablesarenotspacedcloseenoughnoraretheyinvisibleenoughtobeefficientsnares;alsotheprobabilityofabirdflyinginanappropriateareaattherightelevationandattheproperangletothelinesimultaneouslyisrathersmall.Electrocutionofbirdsisalsounlikely;thedistancebetweenlinesandbetweenlinesandgroundisgreatenoughtomakeshortingoutbyabirdalmostimpossible.Birdscansafelyperchoncablesortowers.I -17 Themostsignificantimpactsresultfromhabitatmodificationresultingfromimpactsonsoilsandvegetation.Clearinginforestareasandmaintenanceofasubclimaxplantcommunityofbrushandlowplantswillenhancehabitatbyincreasingtheprimaryproductivityoftheclearedarea.Browseformoosewillbeincreased;theconjunctionofgoodcoverintbeoriginalforestwithaswathofbrowsecreatesadiverse"edge"habitatformanyanimalsdependentonsubclimaxgrowth.Animalsdependentonclimaxornear-climaxvegetationwillsufferlossofhabitat;examplesaretheredsquirrelandnorthernflyingsquirrel.bothofwhichdependuponWhiteSpruce.Destructionofclimacticlichenontundraareaswilldestroywinterbrowseforcaribou.ThedeclineofthecaribouherdsinAlaskaisattributednotonlytohunting.butalsotodestructionoftundralichenbyman-causedfires.Lichenisthekeybrowseforcaribou.foritistheirprimefoodduringthewinter.Itisestimatedthatapproximately50yearsarerequiredforaburne'.areatorecoverausablecoveroflichenforcaribou.Destructionofclimacticvegetationbyfireoftenenhancesmoosehabitat.Taigaecosystemsareadaptedtowildfire.andpresentmosaicsofvegetationcommunitiesareof,enareflectionofformerfires.Anincreaseoffiresresultingfromman-madecauseswill,uptoapoint.havenotmuchmoreimpactthantheincidenceoflightning-causedfires.Asignificantincreaseovernatural-causedfireswillresultinincreasedm·talityfromfires,excessivedestructionofcoverandhabitatfor'''ildlifedependentuponclimacticornear-climacticvegetation.increasedsiltingofriversandlakes.potentialdisruptionofseasonalhabitsandmigrations.andpotentialdisruptionofthepermafrost-vegetationrelationship.Impactuponaquaticlifefromatransmissionlineshouldbesmall.Theaquaticfoodchaininthetaigaandtundraisextremelysimple,andasaresult.disruptionofhabitatforonespeciesquiteoftenindirectlyaffectsmanyotherspecies.Potentialimpactsaretheincreasedsiltationofriversandlakes;alterationofflows;eutrophicationandpollutionoflakesandstreams;disruptionofhabitatduetogravelborrow.fill,andexcavation;andwithdrawalofwater.especiallyduringwinter.I -18 Siltationcanresultfromerosionalongtheconstructionsites,burned-overareas,borrowpits,andrivercrossings.Theimpactofsiltationdependsupontheseverityofsiltation,theexistingwaterquality,andtheamountofaquaticlifeinthestreamorlake.Inriversalreadycarryingglacialsilt,theeffectofman-causedsiltationwillbeslight.Clearwaterstreamsandlakessupportinglargeaquaticpopulationswillbemostaffected.Siltationcancausegilldamageinfishandmayresultinfillingintersticesingravelbeds,reducingsuitabilityforspawning.Alterationofdrainagebyanaccessroadmayinfluenceriverflow,butatransmissionlineprojectshouldnotaffectsurfacedrainagetoanyappreciabledegree.Spillsofoilorfuel,herbicides,andotherchemicalsintowaterbodieswillimpactaquatichabitat.Fast-flowingstreamswillbetheleastaffectedbyspills,duetotherapiddispersalanddilutionofthecontamin-"nt;lakesandslowstreamswillbe'mostaffected.Theactualimpactisdependentuponthetypeofspill,theamount,andthevolumeofwateraffected.Additionofexcessivenutrientsororganicmattertolakes,suchasdisposalof31ash,maycauseeutrophication,eitherfromexcessivealgalgrowthorfromdecompositionororganicmaterial.Excessiveoxygendepletionilllakewaterswillleadtofishkills.Alterationofstreamandlakebedswilldestroyhabitat.Someofthealterations,suchasgravelextraction,willaddaninordinateamount01,'Ittoaclearwaterstream.Aocecondaryimpactofgreatsignificancetowildlifefromatransmissionlinewillbetheincreasedaccesstoareasnowunservicedbyroads.Ifanaccessroadismaintainedforlinemaintenance,itisverylikelythatitwillbeusedbythepublic.BonnevillePowerAdministrationhasexperiencedunauthorizedpublicuseofthoseaccessroadswhicharesupposedlyclosedtoallnon-maintenanceuse.Tomanymammals,thepresenceofmanhasanimpact,particularlythepresenceofhunters.Increasedaccesstopresentlyinaccessibleareaswillcertainlyaddtohuntingpressuresongameinthoseareas.Thedegreeoftheimpactdependsuponregulationbygamemanagementagencies,thequalityoftheareaforhunting,andtheseason.ClimateThiscategoryadherestothedefinitionofclimate,thatis,theaverageweathercor:::litionsoveralongperiod;however,thereareveryfewclimaticdataforthestudyarea.particularlyinregardstowindspeeds.I-19 Thus,eachsegmentisassignedtooneormoreofthreegeneralclimaticzones.ThesearetheTransitional,Interior,andMountainzones.TheTransitionalZoneisamodifiedcontinentalclimate,havingsomeofthecharacteristicsoftheMaritimeZonealongthecoastoftheGulfofAlaska,yetbeingpartiallysubjecttothegreatertemperatureextremesanddrierclimateoftheInteriorZone.Theyearlyaveragetemperatureforthiszoneisabout290Finthenortherlypartto380inthesoutherlypart.Temperatureextremesrangefromabout-400to850F.Precipitationrangesfrom12to24inchesperyear;snowfallrangesfromlessthan50tomorethan200inchesperyear.Windsaregenerallycalm,althoughhighwindsover50mphcanbeexpected.TheInteriorZoneisatruecontinentalclimate.Itisrelativelydry,beingdominatedbyhighpressuJ:el.irmasses.Asaresult,extremeseasonaltemperaturevariationsandrelativelymildwindscanbeexpected.Theyearlyaveragetemperatu:::eforthiszoneisabout240to290F;annualtemperatureextremesrangefrom-600tonearly1000F.Precipita-tionhasanannualrangeofahout8to16inchesayear.Snowfallamountsfromlessthan50toalmost100inchesayear.Windsaregenerallyverylight,withhighwindsrecordedatlessthan50mph.S5-~ethisareaisdominatedbystablehighpressureair,temperatureinversionsarecommon,andventilationislow.ThusthepotentialL"istsforsmog,fog,andice-fogaroundsourcesofparticulatesand/ormvisture.Ice-fogsrepeatedlycoverFairbanksandseriouslyreducevisibility;thetemperatureusuallymustbebelow-350Fforthistooccur.TheMountainZoneisbasicallyamodificationofamoreprevalentzone,inthiscase,eithertheTransitionalortheInteriorZones.Thecausesofthemodificationareelevationandrelief.Increasedelevationtendstolowertheyearlyaveragetemperaturewithoutdecreas-ingseasonaltemperaturevariationspresentatlowerelevations.Highreliefcombinedwithelevationresultsinincreasedprecipitationduetoadiabaticcoolingofupliftedairmasses,andanincreaseintheforceoflocalwinds.Sincemountainousterrainisanythingbutuniform,windpatternscanvarytremendously.However,itissafetoassumehighextremesofwindthroughouttheentirezone.I -20 LandOwnershipandStatusLandownershipisconsiderablylessinfluencedbyphysicalfactorsandmorebysocialfactors.Atpresent,landownershipisanunstablesituation,foralthoughthemajorityofthelandtraversedbytheroutesegmentsispresentlyFederalland,thatratioisdestinedtochange,withmorelandbeinginStateandnativeownership.WiththeexceptionoftheMatanuskaValleyandthemoreheavilysettledareas,thereispresentlyrelativelylittleprivatelyownedland.LandStatusisanevenmorechangingsituationthanlandownership.ThepresentlandstatussituationislargelyaresultoftheStatehoodActof1959,ANCSAin1971,andtheAlaskaConservationActof1974.AllFederallandsinAlaskaarepresentlyinawithdrawalstatus;notonlywillaconsiderableportionofFederallandbetransferredtoStateandNativeownership,butalltheremainingFederallandsareslatedeitherforinclusionintoeithertheexistingNationalsystemssuchsNationalParksandtheNationalForests,orforwithdrawalsforclassificationandpublicinterest.Atpresent,apartfromprivateholdings,onlypatentedStatelandandexistingFederalwithdrawalscanbeconsideredconstant.Mostofthecorridorsegmentslieie,landsthatarependingortentativelyapprovedStateselections,Nativevillagewithdrawals,andNativeregionaldeficiencywithdrawals,allofwhichareinfluxatthepresent.'It;"refore,assessmentofthelandstatusofasegmentreflectsonlyesituationatthetimeofthispublication.Directimpactsonexistingdevelopmentswillgenerallybelow.mainlybecausetherearesofewexistingdevelopmentsalongthesegments.Duetothechangingnatureoflanduseandownership,impactsmaychangeconsiderablyinthespaceofafewyears.Withthepresentpatternoflandownership,therewillbefewconflictswithlandownership,asmostofthelandalongtheroutesarepresentlyinFederalandStateownership.DistributionoflandstoNativesandotherprivateownersbytheFederalandStategovernmentsinthefuturewillincreasethelikelihoodofpurchaseofeasementofprivatelandsandpossiblesubsequentdisplacementofprivateowners.Littleimpactisexpecteduponlanduse;theright-of-waywidthrequiredforatransmissionlineisasmallfractionofthelandthelinetraverses.TherewillJealmostnoconflictwithagriculturalands;atpresent,agricultureisbasicallylimitedtothelowerMatanuskaValley,and smalleral:"easintheTananaandCopperRiverValleys.Thepotentialforagricultureexistsoveraconsiderableareaoftherailbelt(seeFigure9),buttheimpactofatransmissionlineonthesepotentialareasislessthanontheexistingareas.ForestryatpresentisverylimitedintheRailbelt,morefromownershipcausesthennaturalcauses.Forestrycanbeexpectedtoincrease,butimpactsfromatransmissionlinewillbeminimal.Knownandpotentialareasofcoal,oil,naturalgas,andmineralsexistintheRailbeltarea.ThefossilfuelsarepredominantinthethreebasinsoftheTananaRiver,CookInlet,andtheCopperRiverlowland.Mineralsaremoreusuallyfoundinthemoremountainousareas.Atransmissionlineitselfwillhavelittleeffectondevelopmentoftheseresources.TheavailabilityofpowerfromtheUpperSusitnaprojectmightspurdevelopment,butthisisdependentuponthelocalutilitiesandtheirdistributionsystems.LocationofthesemineralresourcesisshowninFigures10,11,and12.Littledirectimpactontownsfromatransmissionlinecanbeexpected;thisresultsfromtheabilitytocircumventthefewtownsencountered.TheendpointsubstationsarpoutsideofAnchorageandFairbanks,sothesetownswillnotbelJenetratedbyaright-of-way.SomeemploymentcanbE'drawnfromcommunitiesontheRailbeltfortheconstructionofthetransmissionline.Largertowns,suchasAnchorageandFairbanks,couldbeexpectedtocontributeahigherproportion0,killedworkersthanthesmallertowns.Sincelinecrewswould.,workingwellawayfromtownsandresidingincamps,theyshouldnetpresentastraintoservicesincommunities.Activitiesassociatedwiththetransmissionlinemaycauseimpactsonservicesincommunities;theseimpactswillprobablyrepresentuseofthecommunitiesgoodsandservices,andifnotaninordinatelylargeuse,willbebeneficialtotheeconomiesofthecommunities.Thus,disruptionoftheeconomiesandservicesofcommunitiesalongtheroutebytheconstructionphaseshouldbelow.Operationandmaintenanceimpactsoncommunitieswillalsobelow;arelativelysmallcrewofworkerscanperiodicallyinspectandmaintainthetransmissionline,andactualoperationswillbeconcentratedinthepowersitesandtheterminalsubstations.Sinceitisrelativelyinefficientforsmallcommunitiestotapatransmissionlineof230kvorhigher,theprobabilitythatthetransmissionlinewillserveadjacentcommunitiesislow.I -22 SOURCE=ALASKAINTERNATIONALRAILANDHIGHWAYCOMMISSIONT_?~oSCALE50Figure9NR100Mils,A.P.A.-JANUARY1975 Figure10U.S.DEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONo1-24 1-25Figure11U.S.DEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONoA.P.A.-JULY1975 Figure12U.S.DEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONIOOMllcsA.P.A.-JULY197550aPOTENTIALMINERALTAREAS1-26 isconcernedwithsu,r:l:aceroutes.Thepossibilityexistsrights-of-wayorsharedaccesswithanexistingtransmissionortransportationcrh,'\,xr::nrsystem,ru"<~"'J""rtPipeline,andhasbeenor,t-'nt-""",',rinwhichatransmis-nr'esenltoccup·anLt.Twoexampleselectricpumpingtransmissionsyst,ernLsthisisamuchtothedifficultyareseveraldefinethispresentvisualscenicvalue,,etc.)aref'X't:!-,f'1rlf'lvalsoseason,weather,themorecomponentsofscenicarescale,intactness,andvividness.isrelationshipofviewedareatotheviewer.Scalesrangedetail,orclose-upviews,asviewssmallelementsofasplants,rockIormations,etc.)toviews,suchasonecouldhaveinaforest,inwhichindividualstillholdmostoftodistantorscenicelementsaretoentirePE:r(:et)tlonofaratherthanperceptionindividualtrees).c1f>.OY'f'f>.ofharmonyamongelementsinalandscape;putdegreeofthelackofdiscordantelements.Aacresisconsideredbymostpeopletobelessdiscordantanlandscapethanafiveacretankfarm.Unityisa,andassuch,isvariablenotonlyamongtheindividualsandgroups,butalsoisvariableovertimeastasteschange. Figure13LOCATIONMAPE380LineLineLineLineA.P.A.-JULY1974604020SKIN)(-l(-)(-X-X33KVTransmission~·-~·-ll.-·-x69KVTransmissionl(_··-X-··-X115KVTransmission~···-x-··-x138KVTransmissionScaleinmileso1-28 Figure14LOCATIONMAP/N NA.P.A.-JULY1974l(-l(-l(-l(33KVTransmissionLineX-·_l(_·_l(69KVTransmissionLinell---l(_.._l(115KVTransmissionLinell-"-l(-"'-l(138KVTransmissionLineUNITEDSTATESDEPARTMENTOFTHEINTERIORALASKAADMINISTRATION1-29NKS Varietyisthedegreeofdiversityinalandscape;itsconverseisuniform-ity,thedegreeofhomogeneity.Varietymaybeafunctionofscale;alandscapeperceivedasuniform,suchastundra,mayhavedetailviewsofamazingvariety,particularlyinitsplantlife.Thereappearstobenoobviousrelationshipbetweenvarietyandunityorbetweenvarietyandintactness.Vividnessisthestrengthoftheimpressionoflandscape.Itisafunctionofthedegreeofpronouncementofthemajorqualitiesinalandscape.Vividnessisinterrelatedwiththecomponentsofunity,intactness,andvariety.Itdoesnotimplystrongvarietyorstronguniformity,butratherthedegreetowhichvarietyoruniformityisperceivedandremembered.Astwoexamples,thehighlydiverseviewofMt.McKinleyasseenfromWonderLakeandthehighlyuniformlandscapearoundLakeLouisearebothveryvividtotheauthor,whereasthelandscapeoflowerTalkeetnaRiverismuchlessvivid.Sincescenicqualityisacomplexsubject,someassumptionsmustmadeinordertouseitascategoryinamatrix.Thefirstassumptionisthatwewillonlybeconsideringlarge-scaleviews;detailandmiddle-viewsshouldnotbeaffectedbyatransmissionline.Second,noattemptwillbemadetoquantifyscenicqualities;thestudyofperceptionisnotyetadvancedtothepointwhereonecanconfidentlyquantifyasubjectofsuchwidelyvaryingindividualperceptions.Third,theareawithinNationalandStateParksorotherscenicreserveswillautoma-ticallybeconsideredmoresensitivetoscenicdegradationbecauseof'eirrecognizedscenicqualities.Fourth,landscapesvisablefrom""'-,.,,,...surfacepublictransportationrouteswillbeconsideredmore.:.ensitivethanthosethatarenot.Thereasoningbehindthisisthatallscenicvaluesarenotintrinsictothelandscape,rather,theyareresponsesoftheindividualsperceivingthatlandscape.Anareawithahighnumberofviewercontactswouldthenbemoresensitivetoscenicdegradationthananareawithnoviewers,orwithveryfewviewers.Obtrusivenessisthelackofunityofanelementwiththerestofalandscape,thedegreetowhichanelementisperceivedasincongruous.Atransmissionlineinavalleybottomseenfromtwomilesawayislessobtrusiveandvisiblethanalinesilhouettedonaridgeonemileaway.Factorsaffectingobtrusivenessaretowerdesignandheight;designandwidthofclearing;reflectivenessoftowerandcable;topography;anddistancefromviewer.Wherenaturalcoverandtopographyenablealinetobehidden,impactonscenicqualityislow;onopentundra,impactwillbemedhlmtohigh,dependingondistanceandtopography.I-30 Thereareseveralrecreationandscenicreservesaffectedbythealterna-tiveroutes;mostimportantareMountMcKinleyNationalParkandDenaliStatePark.Botharerathersensitiveareas,astheyattractandaretheresultofaconsiderabletouristtrade.ParksinAlaskahavetheimageofopen,unspoiledwilderness,particularlytotouristsfromoutsidetheState.Visibilityofatransmissionlineinoraroundtheseparkswillhaveagreaterimpactthaninotherareas.ThereareavarietyofState-ownedrecreationalareasandwaysidesadjacenttothehighwaysintheRailbelt;impactontheserecreationalsiteswillbelow;duetotheirrelativelysmallsize,theycanbecircumventedeasily.TheNationalRegisterofFebruary4,1975listssixregisteredhistoricalandarchaeologicalsitesthatmightpossiblybeaffectedbythealternativeroutes.TheseareshownonFigure15.Inmostcases,impactonthesewillbelowtonone;theotherscanbecircumventedtominimizedisturbance.l11ealternativeroutescrossnoproposedorexistingscenic,wildorrecreationalrivers,nordotheycrossanyproposedorexistingwildernessareasorwildliferefuges.However,insegmentswherethetransmissionlinewillpioneeracorridorthroughapreviouslyintactarea,thequalityofwiUernesswillsuffer,especiallyifthetransmissionlineiseasil-yvisible.However,inmostsegmentsthetransmissionlinewillparallelexistingcorridorsorwilltraversenosignificantlylargeareasofintactwilderness.ApioneercorridorCssingasignificantlylargewildernessareawillhaveahighimpactr'laccessandfuturelocationofotherrights-of-way.TheseinturnwIlldegradewildernessqualityfurther,buttothebenefitofincreasedaccessforrecreationalusesinvolvingmotorizedaccess.Figure16showsanapproximationofexistingscenicquality.I -31 Varietyisthedegreeofdiversityinalandscape;itsconverseisuniform-degreeofhomogeneity.Varietymaybeafunctionofscale;aperceivedasuniform,suchastundra,mayhavedetailviewsofamazingvariety,particularlyinitsplantlife.Thereappearstobenoobviousrelationshipbetweenvarietyandunityorbetweenandintactness.Idnessisthestrengthoftheimpressionoflandscape.ItisafunctiondeOJ"'eeofpronouncementofthemajorqualitiesinalandscape.idne:ssisinterrelatedwiththecomponentsofunity,intactness,and.Itdoesnotimplystrongvarietyorstronguniformity,...",Tho...thedegreetowhichvarietyoruniformityisperceivedandrem(~mbe:re:d.Astwoexamples,thehighlydiverseviewofMt.McKinleyasseenWonderLakeandthehighlyuniformlandscapearoundLouisearebothveryvividtotheauthor,whereasthelandscapeoflowerRiverismuchlessvivid.;:''-C;Leu,,,,,qualityisacomplexsubject,someassumptionsmustintouseitasinamatrix.Thefirstassumptionwewillonlybeconsideringlarge-scaleviews;detailandmiddle-171,p.'l"'<::O;>UU'u.!.\..!.notbeaffectedbyatransmissionline.Second,noattempttoquantifyscenicqualities;thestudyofperceptionisadvancedtothepoi:dwhereonecanconfidentlyquantifyaectsuchwidelyvaryil!gindividualperceptions.Third,theareawithinNationalandStateParksorotherscenicreserveswillautoma-consideredmoresensitivetoscenicdegradationbecauserecogIJlizedscenicqualities.Fourth,landscapesvisablefrom<::11'<1'''''''0publictransportationrouteswillbeconsideredmoresensitivethosethatarenot.Thereasoningbehindthisisthat;';CeIlL:I.Cvaluesarenotintrinsictothelandscape,rather,theyarert::sponsesoftheindividualsperceivingthatlandscape.Anareawithn1:1mberofviewercontactswouldthenbemoresensitiveto"'''_CLLtLdegr'aciat:lo:nthananareawithnoviewers,orwithveryfewnl-,t""""'ven,essisthelackofunityofanelementwiththerestofalandscape,rlPCf,"PPtowhichanelementisperceivedasincongruous.Atrans111issionavalleybottomseenfromtwomilesawayislessobtrusiveandvisiblethanalinesilhouettedonaridgeonemileaway.FactorsalJtec:tll:tgobtrusivenessaretowerdesignandheight;designandwidthreflectivenessoftowerandcable;topography;anddistance.WherenaturalcoverandtopographyenablealinetoIm,pa,ctonscenicqualityislow;onopentundra,impactmediumtohigh,dependingondistanceandtopography.I -30 1-32ngure1::;1U.S.DEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONNATIONALHISTORANDHEOLOGICALSIoA.P.A.-JULY11175 I11:j1ill1~IVSCENICVALUES'OOMUtsSCALE1!!!!!!!!!5__!·!....'---;=-.o50•••••••••••••••'0•......····...·.:i~~~~'jiL(,~~:·...:!I:.··::::.:"--'",,'~__.:,:·~!!~~!i!.!lill!11u.s.DEPARTMENTOFTHEINTERIORALASKAPOWERADMINISTRATIONMAPIlJIDGoodtoHighQualityScenicArea~HighQualityScenicArea1-33 AppendixIIStripMapscoveringtheAlternativeCorridors.Thefollowingstripmapsareinthreegroups:thoseshowingthegeneralfeatures,thosedepictinglandstatus,andthosedelineatingsoiltypes.Thealternativecorridorsarecoveredbysevenmapsforeachgroup;thereissomeoverlapfrommaptomap,butnotallalternativecorridorsareentirelydepictedonanyonemap.Oneachmapisagraystripeshowingtheapproximatepositionofanalternativecorridoronthatmap;thesepositionsareveryapproximate,andtheexactlocationandwidthareindeterminate.ThelandstatusmappedisbaseduponthelandstatussituationofMarch1974.Stateselectionsincludepatented,pending,andtentativelyapprovedState-selectedlands.Duetothepresentunstableconditionoflandstatus,itmustberecognizedthattheremaybechangessincethedateofthemap.Thesoilsmapsarebaseduponthe1:250,000soilsoverlaymappublishedbytheJointFederal-StateLandUsePlanningCommission. INDEXTOALTERNATIVECORRIDORMAPSScaleinmiles5075100125A.P.A.-March1975 AP.A.-March197525201510Scaleinmileso5ANCHORAGE-DEVILCANYON Scalei-10 ScaleinmilesSUSITNAA.RA.-March197515105 I/'v BLAIRLAKEAIRFOReRANGE/::..~~25.i2015nmiles 2520··1510_§galeinmilesINATIONALPA//MOUNTMCKINLEY A.P.A.-Morch1975Scaleinmiles/RANGE,....,..---o510152025 RANGE\ ,.......---o5Scaleinmiles.10 1520 III,RESERVATION~.Q::'~~'.J~.,,>.BLAIRLAKEAIRFORCERANGEFORTGREELY i252015VALDEZ-R-I,.".._.10Scaleinmiles-z.....--..........r:.- miles152025oDPALMER-GLENNALLEN 20:~.~.'~~2=-5_10Scaleinmile~~15/1',-'-<./"/~\\I\~oMOUNTAINS\<.EETNAT~L SOILSLEGENDSoil-eli~__C[))..SlopeGroup-...-----...=<]i)=::TexturalGroupSoilsErosionPotentialEAT-Poorlydrainedsoils,normallyinwaterlaidmaterials.EFT-Welldrainedsoils,instratifiedmaterialsonfloodplainsandlowterraces.EOL-Welldrainedgraysoils;shallowbedrock.EOP-Welldrainedloamyorgravellygraysoils;deeppermafrosttable.HMT-Poorlydrainedpartiallydecomposedpeat;seldomfreezesinwinter.HMV-Poorlydrainedpartiallydecomposedpeat;containslensesofvolcanicash.HY(B)G-Poorlydrainedfibrouspeat;freezesinwinter.HYP-Poorlydrainedfibrouspeat;shallowpermafrosttable.IAHP-Poorlydrainedsoilswithpeatysurfacelayer;shallowpermafrosttable.lAP-Poorlydrainedsoils;shallowtodeeppermafrosttable.lAW-Moderatelywelltopoorlydrainedsoils;maycontaindeeplyburiedicemassesICF-Welldrainedbrownsoils;containslensesoffine-grainmaterial.ICP-Welldrainedthingrownsoils;deeppermafrosttable.ICT-Welldrainedgrownsoils;non-acid.IND-Welldraineddarksoilsformedinfinevolcanicash.IUE-WelldrainedsoilswithClark,acidsurfacelayer.IUL-Welldrainedsoilswithdark,acidsurfacelayer;shallowbedrock.IUP-Welldrainedthinsoilswithdarkacidsurface;deeppermafrosttable.RM-Verysteep,rocky,orice-coveredland.SOPWelldrained,thin,stronglyacidsoils;deeppermafrosttable.SC":.-Welldrainedstronglyacidsoils.SOU-Welldrained,stronglyacidsoils;verydarksubsoil.Themappingunits,whilereferringtoonlyoneortwodominantsoilsintheassociation,includeothersoilsandlessextensivesoils.SlopeGroups1 -Slopesdominatelylessthan12%.2 -Slopesdominatelysteeperthan12%.TexturalGroupsc -sandyf -clayeyErosionPoten'ialg -verygravellym-loamy(medium)E-1-lowE-2-mediumE-3-high RMA.P.A.-March1975SOILS:ANCHSOU-HYCB)G2mE-2Scaleinmileso5,1015~:z=nSJOT-HYCB)G1mE-I,2 SOT-HY(B)G2gE-2RM2.Q!-HY(B)G1mE-I,2\=Scalei IUL_RM29jI(;IAHP_EOPE-21mAf9-MorCh1975SOILS:SUSITNA IUL_RM20I;I/! -EOL~O-21miles1520ICF-IAHP---2m1mE-2,3 ScaleinmilesRM101520JAI:l1mE-: ERMSOP_IAHP2g10~1fiiiii~~:IIIIIii_iiiiiiII-~~~~~~~~iiiiiiiiiiiii~~~~i9/5101520r-_.:;;.;25~-::J_,A.I?A.-Morch1975SOILS:,CANTWELL-PAXSON !.Y.b-RM20E-IRM lAW_leTE-21m10RM--..-P'""'l-so10RM ICT-IAHPE-2,32g1mICFIAHPE-2,32m-1mIAHPE_21mICTIAHPE-2Ig-2m SOILS:VALDEZ-IAliPE-2If~E-320IAHPE-21mIAHPE-2IfWIAHPE-,2Ifo51015 RMRMRMIUP-IAHP2gE-2,3l.A1iPE-2If!!!fE-320!AHPE-21m DIAHPIfE-2SOILS:PALMER-GLENNALLENRM25.......1IUP-IAHP2gE-22015miles7 RM.··25IUP-IAHP20E-2201510Scaleinmile~RMRMRMRMRMSOU-IUL20E-I LANDSTATUSLEGENDMajorwithdrawalspriortoAlaskaNativeClaimsSettlementAct,(December18,1971)WithdrawalsforpossibleinclusiononthefourNationalsystems(D-2)mWithdrawalsforclassificationandpublicinterestCD-I)-----------------------Stateselections-patented,tentativelyapproved,andpending(8S)WithdrawalsforNativevillageseligibleforlandselectionsWithdrawalsforNativevillages,eligibilityforlandselection.notfinallydeterminedVillagedeficiencywithdrawals(NVD)Regionaldeficiencywithdrawals(NRD)Utilitycorridor(UC)The,<emapsrepresentthelandstatussituationasdeterminedbytheBureauofLandManagement,December18,1973 0-2··~oa"""""""'~25~N,-•CANYONA.A-M","1975ORAGE-DEVILD0STATUS:ANCHLAN LScaleinoo55'..~Eklutna MACLARENRIVER_:2025AP.A.-Morcll1975:SUSITNAMACLARENRIVER_:2025AP.A.-Morcll1975:SUSITNA 55A.P.A-Morch1975MilitaryReservationLANDSTATUS:CANTWELL-FAIRBANKS5nmiles~i15'2025 Mt.McKinleyNotionalPork/)55,Scaleinmiles-:101520-25 55Scaleinmiles,<!PNRDLANDRANGEALASKA 5555Scaleinmiles25--10151"'"""1150LAND 55MilitaryReservation55MilitoRryeservation ssssNRDoScaleinmiles510 152025LANDSTATUS:VALDEZ-P,""""",,,,. •NRDNRD\55.!G4a~rt~.~BI;\\\\illt•Gakonc NRD252015c:>~'V~Ii'adO'0""o(J\j0Ii'•.t>"'"I)~sso0~1milesLANDSTATUS,PALMER-GLENNALLEN 10a::'::::\h:f,~\l\;i::;;:::~NRDi20--25/"Scaleinmiles~-1555~/"~ APPENDIXIIII1IJ]JI]JJIJJ1------' l]1I1J]1j1JIAPPENDIXIIIPhotographsThefollowingphotographsdepicttypicalviewsandcriticalpointsalongtheproposedcorridorsandtheiralternatives:Photos1 - 4areillustrationsofCorridorSusitna-1Photos5 -25areillustrationsofCorridorNenana-1Photos26-28areillustrationsofCorridorSusitna-2Photos29-30areillustrationsofCorridorSusitna-3.4Photos31-40areillustrationsofNenana-2.3.4.5Photos41-56areillustrationsofMatanuska-1,2Photos57-69areillustrationsofDeltaCorridorAllphotographsinthisappendixweretakenbyAPApersonnel.ThemajorityweretakeninSeptemberof1974. JJJ]1]J]J]]JJ1LowerSusitnaRiverValley.Thisareaischarac-terizedbyextensivemuskegs,intermingledwithbottomlandspruce-poplarforests.Pennafrostisabsentordiscontinuousinthisarea,althoughthesoilsaregenerallypoorlydrained.III-l ]l~lIJJ1]]]JISusitnaRiverValley.Lakesareprevalentandassoc-iatedwithmuskegs,whichsucceedtheminformation.Muskegsaresucceededintumbyforestsdependentuponwell-drainedsoils.Thethreestagesofsuccess-ionareshownhere.III-2 J1J1]]]JJLJJJ]]]IjISusitnaRiverValleynearTalkeetna.Astheterrain,becomesmorerolling,therelativeamountofmuskegbecomesless.III-3 L-...L...:L...--;L-...L-.....L..:c..::...J L..J E.....:J LJ ---'- ............... I... Town of Talkeetna.This town is at the confluence of the Talkeetna, Susitna,and Q1Ulitna Rivers.The Alaska Railroad can be seen cross- ing the Talkeetna River near the right edge of the picture. ~L-:L...."----''----''----'L..J "----' ............... I <n Summit Lake at Broad Pass.Broad Pass is an aptly named feature;a structurally-controlled depression in an othen~ise mountainous area. It is the divide for tributaries of the OlUlitna and Nenana Rivers. '----'~L..:~'----''----' ~ ~ ~, '" ....«.....~ '"'-- . ~lF -.• -- Alaska Range from Andlorage-Fairbanks Highway near Broad Pass,late spring.Vegetation biorne is lowland spruce-harm,ood.Soils here are basically glacial deposits. L.--~L.-----..l '----'::.:.......J --..J --..J ---I...., Alaska Range from Anchorage-Fairbanks Highway near Broad Pass.Soil here is poorly drained;trees visible are black spruce. L..-'--L.....:'---------...-'---'---'....................J ---.J ---' ~ ~ ~ I CO Entering Alaska Range on Anchorage-Fairbanks IIighway,north of Cantwell. Concealment of line will be difficult in areas such as this. 1llJ1JJJJJJJLookingsouthalongNenanaRivertoUpperNenanaCanyon.TheAnchorage-FairbanksHighwayparallelstheleftbank.MountMcKinleyNationalParkandtheAlaskaRailroadareontherightbankoftheriver.II1-9 ~~~t..........J ----'----... ......... I ~ <:) Nenana River and Sugar Mountain,seen from Andlorage-Fairbanks Highway near Yanert.Yanert Fork enters Nenana River near right-hand edge of photo.Visible also is communication line for Alaska Railroad. ]J]JJJJVeryrestrictedcanyonalongNenanaRivernorthofMcKinleyPark.AlaskaRailroadisoffleft-handedgeofphoto.LandleftofriveriswithinMountMcKinleyNationalPark.II1-11 ]J..<f~~.....,UJIII-12L...:L...::LJ Another view of canyon on Nenana River. JIII-13,Cllco~0{j]~§CllCO."''';H.noS0~4-<0C''';.~U''';>~''';~.:::~~~COH''';~:r:~~)@OB~''';Cll«lZ~J]JJL..: Nenana River valley in vicinity of Moody bridge on Anchorage- Fairbanks Highway. lllJ]1:«lP..~..-<.S;.,:~4-<0.cJ..,f.<0~~0\f.<..-<\.....~J«l""~..-<J~\1]11JIII-14JAlaska Railroad north of McKinley Park. L.-L-...------L--'----'L..J L......J :..-.J ----' ---I ~ '" Usibelli Coal Mines near Healy.Note the seams of coal in the scarp.This coal is the fuel for the Healy steamplant. L-~"---'~~"'"---L.J ~LJ '----'~.......--.......-- ~ ~ ~ I ~ en Nenana River flood plain near Healy.Note the terraces characteristic of the Nenana Valley in this area. L-~L------'---'---....---....L..:------c::J ~..........J ---I ~-... 138 KV Healy transmission line.Looking south from Anchorage- Fairbanks Highway towards Healy. 1],.'"l".,'\''IJ]JJJJJIGuyedtangenttowerinforegrOl.D1d;guyeddead-endtowersinbackground;Healy138KVtransmissionline.1II-18 1J]]I11JjJJ1JJGuyed138KVtowerontheHealytransmissionline.III-19 L-L-L....;~L..-.2 :....-.J L....J ~ ~ ~ ~ I Na Nenana River valley,looking south to Alaska Range.Terraces are fairly evident along right background. nJ]JJJJTownofNenana,atconfluenceofTananaRiverandNenanaRiver,whichflowsinfromlowerright.Double-spanbridgeisfortheAnchorage-FairbanksHighway;single-spanbridgeisforAlaskaRailroad.III-21 ..........'--l......-...'--'--i--..-J i--..-J ~........i--..-J ---'~=----:J ---I N N Alaska Railroad siding along Tanana River at Nenana.Large free- standing ta~er is part of river crossing of Healy 138 KV transmission line. ~L-'---'---L-:L-J ::.:.::J ..........~~'iI...o--.oi =--.J ~ ~ ~ I N W Town of Nenana;frontage on Tanana River.Nenana handles considerable river traffic on the Tanana River. '--L.--...'--L......L.--...'---'L..J C-..J '---=-.J ---I N..,. "Golds tream Hills".On the slopes,the predominant vegetation is birch-white spruce,on poorly drained areas and some north-facing slopes;black spruce predominate. '---L-'--'--'---~'---':...-J ---I N '" View to the west from the "Goldstream Hills".These hills flank the north bank of the Tanana River;the Anchorage-Fairbanks Highway enters them immediately across the river from Nenana,and follows their crest to Ester and Fairbanks. \.-.--0 ~~"--'-------------::.....-.J ~ ~ ~ I N 0'> Clearing for ~latanuska Electric Association (MEA)distribution line. Vegetation is predominantly poplar and spruce.Clearing was done by uprooting trees with a bulldozer. L-L.-L.-L..-...-LJ L.:.J ~---J ............ I I\)..... Near Honolulu on the Anchorage-Fairbanks Highway.Biomes shown on low brush muskeg in foreground and upland spruce-hardwood in back- ground.Black spruce in foreground are associated with poorly drain- ed soils and/or shallow permafrost tables. J]JJJJJJJJJJJLittleCoalCreekinDenaliStatePark.Vegetativebiomeisclassifiedasuplandsprece-hardwood.Streamsinthisareaareincisedintoarelative-lygentleplain.,III-28 ]]]1JJJTalkeetnaRiverneartownofTalkeetna.ThisphotoshrnvsthedensityandconformityoftheforestofthelowerSusitnaValleyintheTalkeetnaarea.111-29 L.....e.-L.....~L....l ~L..J LJ ::::....J ~ ~ ~ I Wa Detail of bottomland forest near Talkeetna.Predominant trees are poplar and white spruce with considerable brush understory.This forest type can easily conceal a transmission clearing. lll]1]JJJJJUpperWellsCreek,approachingpasstoLouisCreek.Biomeisalpinetundra.III-31 1l]l1]JJJ]j]JJJJrrI-32Q)-.l'MUl~Q)Q)GUlOM;:l.3]\3Q)UlWells Creek Pass as seen from Louis Creek side. L....L-:~E..-L....:L........J '-----' I ~~L.:..:l ~ ~ ~ ~ I W W Moody Pass from Yanert Fork to Moody Creek,.which is visible in the upper left.This pass is relatively low (2900')and wide,but soils are poorly drained and subject to permafrost. L....,;L....---....c........:L...j ~ "" L.J L.J "'"""--' ~ ~ ~ I W..,. Lower Moody Creek.This upland spruce-hardwood. cult in this stretch. is a well-dissected area,covered with Routing of transmission may prove diffi- ]]]]JIJ1JJLCMerMoodyCreekatconfluencewithHealyCreek(topofphoto).Unstableslopesareevident.1II-35 L....:L--L-L-..]L.-...,;.................................. ---I W CT> Looking north from western end of Denali Highway.Typical low brush and muskeg biomes.Trees are black spruce. 11J]JJ1JJJAerialviewlookingwestalongDenaliHigrn,ayandNenanaRivertoCantwell.Notethatforestsarelimitedtotheterraceslopesandleveesoftheriverchannel.II1-37 "'----L-L--'---i '---i ---.............-..........'---'---.............J ...........J ---I W 00 Surface view of area typical of that shCMIl in photo above;in this case,the Nenana River is in the vicinity of the Wells Creek con- fluence.The lowland spruce-hardwood is limited to the terrace slope and river bottom. '--'--'--'----'r-....;----''--'.........L..J '---'~ ............ I tAl \0 Looking west up the Nenana River and Denali Highway.The sources of both the Nenana and Susitna Rivers are in the Alaska Range visible in the upper left.In the upper left also is the divide between these two rivers,a wide,poorly-drained area called Monahan Flat. n1]JIJJjJJSusitnaRiverbetweenWatanaandVeedamsites.Heaviervegetation,inthiscaseuplandspruce-hardwoodforest,islimitedtothevalleyslopes,thevegetativebiomeontheupperplateausisgenerallymoisttundra,muskeg,andalpinetundra.II1-40 l-~L.....::~~~~ ~ ~ ~ I... ~ Susitna River at Vee damsite.This demonstrates the typically in- cised character of the Upper Susitna from Devil Canyon to the Tyone River.Note that heavier vegetation is limited to slopes and creek valleys. JJJJ]JJ]]J]JJJobisttundranearButteLake;lookingnorthtoMm.ahanFlatsandAlaskaRange.JJVtracksarevisibleintheforegrowd;thesetracksstart:fraDtheDenaliHighway,whichcrossestheflatsinthebackgromd.II1-42 l1]I]JJJJJJATVtracksleadingfromDenaliHighway.Thisphotoshowstypicalmoisttundravegetationwithlow-growingbrush,peatysoil,andpoordrainage.II1-43 L....::L..-.....E...-....:L..J ~..........L.J :.--.J ---I ~ ~ Susitna River above Denali damsite,looking west.The few spruce to be found are limited to the river bottom. L....-'-'-'-L..:-----'-......................-::....:.J -------- ............ I -l>o '" Impoundment area of Denali damsite.The Susitna here is a meandery,' aggrading river,the surrOlmding land is very poorly drained and underlain by fairly continuous permafrost. '--'----...'--L....J '---'--...--...:......J ~ ~ ~ ~ I.;.. '" Maclaren River,looking north to the CleaIWater Mountains.The fore- ground knob is part of a morainal ridge.These morainal features are reltaively well-drained,whereas the flat low-lying lands are poorly drained with shallow permafrost tables. L....:L-<...--.0 "----L.J "---'L.:L......:~ ---I........ Looking north along the Denali Highway to the Amphitheater MOl.D1tains. Morainal ridges run across the middle of the photo.The biome along most of the eastern half of the Denali Highway is moist ttmdra. ~~~..........~ l---J _........... ............... I... 00 Uplands near Sourdough on the Richardson Highway.This is typical of the plateau bordering the Copper River lowland on the north and east. Poorly drained,it supports many lakes,the largest of them in the Lake Louise complex. L......L-L.....L.....L.J c..:J ~L.J :........J ~ ~ ~ I .j:> <0 The Lake Louise plateau.Biomes are predominantly lowland spruce- hardwood and muskeg.These uplands are underlain by continuous permafrost. 1JI]~Ul01~~Q)0-J>...0.~]0:1.-<MQ)"CJ§J.~~.0JQ)bI)1;;.-<0:1J.~§.-<]6.-<MQ)J>.....<:>:MQ)j~uQ)~]JI]III-50J-- --- The Copper River lowlands,a large basin tmderlain by pennafrost. l11J]JJTazlinaRiverasseenfromtheGlennHighway.III-51 "--~"--~~----~------'=-...:J ----' ---•<.11 '" Tahneta Pass area between the Tazlina and ~1atanuska River drainages. Lakes and muskegs are indicative of poor drainage.The mountains are part of the OlUgach Range. JlJ]]]J1JJTalkeetna~lountains;GlermHig4wayrunsacrossthelowerportionsofthephoto.TheMatanuskavalleyisborderedonthenorthbytheTalkeetnaRange,onthesouthbytheQmgach.III-53 ---....~t.....-J L.........:l ~~r 1 -...J ~ ---I '"... HCMell Glacier and the QlUgach Range.The Matanuska River flCMS in an incised channel across the middle of the photo. :ll]J1]11]1IICaribouCreekandtheTalkeetnaMountains;GlermHighwayonlowerportionofphoto.ThistributaryoftheMatanuskaRivertypifiestheincisedcharac-terofmanyriverserodingthroughglacialdebrisandloess,suchastheMatanuska,Copper,Gulkana,andupperNenanaRivers.III-55 -lo--..i r....-...J --.J L.-..J ~~L...J ~~ ~ ~ ~ I 01 '" ~latanuska River and OlUgach Range.The Matanuska River has a braiding channel due to the high silt load from the Howell and r.latanuska Glacier,and the glacial tributaries entering from the Chugach Range. -------.J ~~~---..~--..; ---I 01 -..J Looking north by Paxson Lake on the Richardson Highway to the Alaska Range.Paxson Lake is an important part of the fisheries of the Gulkana River. '--~L..:'--'--"----'C-.J L.J L.J LJ ""----'L...J ---.J ~ ~ ~ ~ I <11 00 Sununit Lake and the Alaska Range.Summit Lake is drained by the Gulkana River and is just south of Isabel Pass. :.....=J L-L-:'---''--'I.....-J L......:LJ L.J ----'::.:...:.J c.....:...J ~ ~ ~ I U1 ID Isabel Pass,looking north to Rainbow Ridge.The Richardson High- way,the Delta River,and the Alyeska Pipeline cross the plloto at the base of RainbOW'Ridge. ----____~L....-J L...J L...J ::::.::J L...:L..J ::....::.J '---' ~ ~ ~ I C>o RainbCM Ridge,as seen from the south.The Richardson Highway crosses under the ridge from right to left.The slope of the ridge is a series of adjoining talus cones some of which are unstable. L-.L-."----"L-.............. ~-...... I 0'> ~ , ..... f"'~ --k::eup--... .to Delta River by Black Rapids Glacier.The glacier is partially visible in the upper center of the photo.The Delta River carries considerable ,glacial silt,resulting in aggradation and braiding of the channel. ~L...-'---~~'----''---'::..:...J ............... I 0> N Alaska Range seen fran the north from the Richardson Highway.This is not true perspective as seen from the highway.since the photo was taken with a telephoto lens.- '----'---~~...........~~...........J ~ ~ ~ I '"W The Alaska Range seen from the Richardson Highway near Donnelly Dome, looking south.The dust i:;from the channel of the Delta River,which is extremely undersized fo:r its channel. '-----~~~.'-----L..:----..I ~:.......J ............... I 0'>.... Another view of the Delta River as seen frcm near Donnelly Dome. Again,the blCMing dust from the charmel is evident. ~L.....~'-----'C-..J "-----c...:J ~-----' ---Ien 01 Alaska Range from Big Delta,taken with telephoto,In the foregrOlmd is the Delta River channel,which near here joins the Tanana River. L-L...: ............ Imm ----L-.:~~ '----'L..J L-J ..........~'.-J L.J Fann near Delta Junction.Some attempt at fanning is made in the ClealWater Lake area,but agriculture is relatively unimportant except for the lower Matanuska Valley area. J]J]IJ]]]]J1II1-67.11l.~.....§....'5.0............VI....'"Silhouetted notch on a clearing for a GVEA distribution line. 1j]JJJLookinguptheTlIIIlIDllRiveracrosstheconfluenceofShawCreek.ThebraidingofduamelscharacteristicoftheDeltalindTananaRiversisevident.II1-68 The Tanana River flood plain.This area is extreme- ly flat and poorly drained.Three types of biome are represented in this picture:muskeg,lowland spruce-hardwood,and bottomland spruce-poplar.The dark forests are mainly black spruce.The sinuous lighter forest is white spruce,aspen and birch. This forest type prefers well-drained soils,and so is found on old levees of existing and extinct channels. 111-69