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Scour-Critical Bridges in Alaska

Alaska has 149 bridges rated scour-critical by the Federal Highway Administration. These bridges have foundations that are unstable or at risk of undermining during flood events. Scour-critical doesn't mean a bridge is about to collapse — it means extra monitoring and countermeasures are in place — but these structures are priorities for repair or replacement.

How this ranking works

This state list filters to NBI scour ratings 0 through 3, then sorts by average daily traffic. It is intended to show flood-vulnerability exposure, not to label any bridge as currently unsafe.

BridgeCountyScour RatingDaily TrafficCondition
Minn DR S.b. over Campbell CR Minn DR S.b.Anchorage3 — Serious13,900Fair
Minn DR N.b. over Campbell CR Minn DR N.b.Anchorage3 — Serious13,900Good
A ST over Chester CreekAnchorage3 — Serious10,700Fair
North Tongass HWY over Carlanna CreekKetchikan Gateway3 — Serious9,210Fair
Minn-dimnd Offramp over Campbell Creek SB RampAnchorage3 — Serious5,660Good
Dimnd-minn On-ramp over Campbell Creek NB RampAnchorage3 — Serious4,690Fair
Sterling Highway over Kenai River (schooners)Kenai Peninsula3 — Serious2,900Fair
Fair Street over Ketchikan Creek Fair STKetchikan Gateway3 — Serious2,480Fair
Park Street over Ketchikan CR Park-upperKetchikan Gateway3 — Serious2,298Fair
Ballaine Road over Goldstream CreekFairbanks North Star3 — Serious2,080Fair
Richardson Highway over Tanana River Big DeltaSoutheast Fairbanks3 — Serious1,990Fair
Parks Highway over Nenana River Park BndDenali3 — Serious1,680Fair
Parks Highway over Antler CreekDenali3 — Serious1,380Fair
Parks Highway over Bison GulchDenali3 — Serious1,380Fair
Klondike Highway over Skagway RiverSkagway3 — Serious1,200Fair
Nash Road over Salmon CreekKenai Peninsula3 — Serious1,180Fair
Parks Highway over Chulitna RiverMatanuska-Susitna3 — Serious1,120Fair
Gustavus Airport R over Salmon RiverHoonah-Angoon3 — Serious1,020Poor
Parks Highway over Bear CreekDenali3 — Serious910Fair
Parks Highway over East Fork Chulitna RiverMatanuska-Susitna3 — Serious900Fair
Glenn HWY Spur over Little Nelchina RiverCounty 0663 — Serious765Fair
Irr:nknk-kng Salmn over King Salmon CreekBristol Bay3 — Serious760Good
Plumley Road over Bodenburg CreekMatanuska-Susitna3 — Serious660Fair
Chiniak Highway over American RiverKodiak Island3 — Serious600Fair
Chiniak Highway over Small CreekKodiak Island3 — Serious600Fair
Halibut Point Road over Starrigavan CreekSitka City and3 — Serious560Fair
Irr:old Align Rich over Klutina RiverCounty 0663 — Serious480Fair
Chiniak Highway over Deadman CreekKodiak Island3 — Serious470Fair
Chiniak Highway over Olds RiverKodiak Island3 — Serious470Fair
Richardson Highway over Tiekel River Upper XingCounty 0663 — Serious440Good
Anton Larsen Bay over Buskin River No 6Kodiak Island3 — Serious380Fair
Haines Highway over Chilkat RiverHaines3 — Serious340Fair
Basin Road over Gold CreekJuneau City and3 — Serious280Fair
Richardson Highway over Castner CreekSoutheast Fairbanks3 — Serious280Poor
Richardson Highway over Trims CreekSoutheast Fairbanks3 — Serious280Fair
Richardson Highway over Michael CreekSoutheast Fairbanks3 — Serious280Fair
Richardson Highway over Flood CreekSoutheast Fairbanks3 — Serious280Fair
Richardson Highway over Boulder CreekSoutheast Fairbanks3 — Serious280Fair
Tok Cutoff over Indian RiverCounty 0663 — Serious260Good
Kenai Spur over Swanson RiverKenai Peninsula3 — Serious260Fair
Irr:nome-taylor RD over Grand Central RiverNome3 — Serious249Good
Richardson Highway over Gunny Sack CreekSoutheast Fairbanks3 — Serious240Fair
Monashka Bay Road over Monashka CreekKodiak Island3 — Serious220Fair
Alaska Highway over Johnson RiverSoutheast Fairbanks3 — Serious180Poor
Alaska Highway over Gerstle RiverSoutheast Fairbanks3 — Serious180Poor
Petersville Road over Moose CreekMatanuska-Susitna3 — Serious160Poor
Taylor Highway over Taylor CreekSoutheast Fairbanks3 — Serious160Poor
Steese Highway over Mammoth CreekYukon-Koyukuk3 — Serious140Fair
Dalton Highway over Ft. Hamlin Hills CreekYukon-Koyukuk3 — Serious140Fair
Dalton Highway over Trevor CreekNorth Slope3 — Serious130Fair
Dalton Highway over Dan CreekNorth Slope3 — Serious130Fair
Steese Highway over Sourdough CreekFairbanks North Star3 — Serious120Good
Circle Hot Springs over Deadwood CreekYukon-Koyukuk3 — Serious120Fair
Circle Hot Springs over Ketchum CreekYukon-Koyukuk3 — Serious120Good
Dalton Highway over West Fork N Fk ChandalarNorth Slope3 — Serious110Fair
Irr:steese Highway over Birch CreekYukon-Koyukuk3 — Serious110Fair
Dalton Highway over Mid Fork Koyukuk River 2Yukon-Koyukuk3 — Serious110Fair
Dalton Highway over Gold CreekYukon-Koyukuk3 — Serious110Good
Doughchee AVE over Beaver Springs CreekFairbanks North Star3 — Serious100Fair
Bruno Road over Glacier Fk Of Salmon CRKenai Peninsula3 — Serious100Fair
Copper River HWY over Copper DeltaCounty 0633 — Serious94Good
Lutak Spur over Chilkoot RiverHaines3 — Serious90Fair
Irr: Airfield RD over Gold CreekYukon-Koyukuk3 — Serious86Poor
Irr:airport Road over Perryville CreekLake and Peninsula3 — Serious77Good
Sand Point Road over Humbolt SloughAleutians East3 — Serious75Poor
Mineral Creek Road over Mineral CreekCounty 0633 — Serious75Poor
Edgerton/mccarthy over Gilahina RiverCounty 0663 — Serious70Fair
Irr:kasaan Road over Tolstoi Creek No. 1Prince of Wales-Hyder3 — Serious70Good
Irr:kasaan Road over Tolstoi Creek No. 2Prince of Wales-Hyder3 — Serious70Good
Irr:kasaan Road over Tolstoi Creek TributaryPrince of Wales-Hyder3 — Serious70Good
Copper River HWY over Million Dollar BridgeCounty 0633 — Serious65Poor
Copper River HWY over Copper DeltaCounty 0631 — Imminent failure65Poor
Denali Highway over Susitna RiverMatanuska-Susitna3 — Serious60Poor
Irr:airport Road over Unnamed Creek KoliganekDillingham3 — Serious50Poor
Running Water AVE over Crooked CreekKenai Peninsula3 — Serious50Fair
Brody Lane over Ninilchik Riv Brody LNKenai Peninsula3 — Serious50Good
Irr:newhalen Road over North Fork Alexcy CreekLake and Peninsula3 — Serious50Fair
W Demaree Circle over Cottonwood CreekMatanuska-Susitna3 — Serious50Fair
Irr:nome-taylor RD over Pilgrim RiverNome3 — Serious50Good
Irr:anderson RD over Indian CreekLake and Peninsula3 — Serious45Poor
Irr:anderson RD over Chignik CreekLake and Peninsula3 — Serious45Fair
Sterling L/ophir over Tatalina RiverYukon-Koyukuk3 — Serious45Fair
Sterling L/ophir over Yankee CreekYukon-Koyukuk3 — Serious45Fair
Sterling L/ophir over California CreekYukon-Koyukuk3 — Serious45Poor
Sterling L/ophir over Ganes CreekYukon-Koyukuk3 — Serious45Fair
Sterling L/ophir over Spruce CreekYukon-Koyukuk3 — Serious45Poor
Sterling L/ophir over Independence CreekYukon-Koyukuk3 — Serious45Fair
Chignik Lagoon over Packers CreekLake and Peninsula3 — Serious41Fair
Copper River HWY over Copper Riv (flag Pt Wst)County 0633 — Serious40Fair
Copper River HWY over Copper Riv (rnd Island)County 0633 — Serious40Good
Copper River HWY over Copper DeltaCounty 0633 — Serious40Fair
Copper River HWY over Copper DeltaCounty 0633 — Serious40Fair
Copper River HWY over Copper River (flag Pt E)County 0633 — Serious40Fair
Dangerous River RD over Situk RiverYakutat City and3 — Serious40Fair
Wiseman Road over Wiseman BridgeYukon-Koyukuk3 — Serious40Fair
91 Mile Loop over Little Tok OverflowCounty 0663 — Serious30Good
Cache Creek Road over Spencer CreekFairbanks North Star3 — Serious30Fair
Standard Creek RD over Standard CreekFairbanks North Star3 — Serious30Poor
Cache Creek Road over Fortune CreekFairbanks North Star3 — Serious30Good
Cache Creek Road over Kari CreekFairbanks North Star3 — Serious30Fair
Williamsport/pile over Chinkelyes CreekKenai Peninsula3 — Serious20Fair
Williamsport/pile over Four Mile CreekKenai Peninsula3 — Serious20Good
Tall Trees Road over Stariski CreekKenai Peninsula3 — Serious20Fair
Kenai Spur HWY Ext over Lief CreekKenai Peninsula3 — Serious20Fair
Kenai Spur HWY Ext over Otter CreekKenai Peninsula3 — Serious20Fair
Williamsport/pile over Timberline CreekLake and Peninsula3 — Serious20Good
Shirley Towne DR over Willow CreekMatanuska-Susitna3 — Serious20Fair
Taylor Highway over Forty Mile RiverSoutheast Fairbanks3 — Serious20Good
Standard Creek RD over Dunbar CreekYukon-Koyukuk3 — Serious20Good
Irr:deering Road over Smith CreekNorthwest Arctic3 — Serious18Fair
Irr:kingkingin RD over Village CreekNome3 — Serious16Fair
Irr:airport RD over Crooked CreekBethel3 — Serious15Fair
91 Mile Loop over Trail CreekCounty 0663 — Serious15Fair
IRR BIA RTE 22 over Small Point CreekPrince of Wales-Hyder3 — Serious15Fair
Irr:tetlin Road over Tetlin RiverSoutheast Fairbanks3 — Serious14Fair
Irr:airport Road over Shageluk SloughYukon-Koyukuk3 — Serious11Poor
Irr:chenega RD over Chenega CreekCounty 0633 — Serious10Fair
Irr:kolgnk Dump RD over Unnamed CreekDillingham3 — Serious10Poor
Logging Road over Jenny M CreekFairbanks North Star3 — Serious10Good
Dalton Trail Spur over Little Salmon RiverHaines3 — Serious10Fair
Dalton Trail Spur over Clear Creek (haines)Haines3 — Serious10Fair
Porcupine Road over Porcupine CreekHaines3 — Serious10Fair
Porcupine Road over Bear CreekHaines3 — Serious10Fair
Porcupine Road over Glacier CreekHaines3 — Serious10Good
Chakok Road over North Fork Anchor RiverKenai Peninsula3 — Serious10Fair
Dorothy Drive over North Fork Anchor RiverKenai Peninsula3 — Serious10Fair
Lee Roy Avenue over Henry CreekKenai Peninsula3 — Serious10Fair
IRR BIA RTE 1026 over Unnamed CreekKenai Peninsula1 — Imminent failure10Poor
Bostwick Lake Road over Bostwick No. 1Ketchikan Gateway3 — Serious10Fair
Bostwick Lake Road over Bostwick No. 2Ketchikan Gateway3 — Serious10Fair
Bostwick Lake Road over Bostwick No. 3Ketchikan Gateway3 — Serious10Fair
Bostwick Lake Road over Bostwick No. 4Ketchikan Gateway3 — Serious10Fair
Bostwick Lake Road over Bostwick No. 5Ketchikan Gateway3 — Serious10Fair
Bostwick Lake Road over Bostwick No. 6Ketchikan Gateway3 — Serious10Fair
Collinsville Trail over Peters CreekMatanuska-Susitna3 — Serious10Fair
Midnight Drive over Georges CreekMatanuska-Susitna3 — Serious10Fair
Snowball Court over Georges CreekMatanuska-Susitna3 — Serious10Fair
Kake Access - Usfs over Creek Name Not ListedPetersburg3 — Serious10Fair
Kake Access - Usfs over Creek Name Not ListedPetersburg3 — Serious10Fair
Kake Access - Usfs over Creek Name Not ListedPetersburg3 — Serious10Fair
Dyea Road over Nelson SloughSkagway3 — Serious10Fair
Happy Creek Road over Otter CreekYukon-Koyukuk3 — Serious10Poor
Irr:airport Road over Mukluk CreekYukon-Koyukuk3 — Serious10Fair
IRR BIA RTE 26 over Unnamed StreamPrince of Wales-Hyder3 — Serious5Fair
IRR BIA Route 008 over Unnamed CreekPrince of Wales-Hyder3 — Serious1Poor
IRR BIA Route 008 over Unnamed StreamPrince of Wales-Hyder3 — Serious1Fair
IRR BIA RTE 27 over Unnamed StreamPrince of Wales-Hyder3 — Serious1Poor
Logging Road over First CreekHaines2 — Critical0Poor
Fdr 6540 over Stream - Hamilton 60r36Wrangell City and3 — Serious0Poor