US Bridges

Irr:ocean Cape RD over Ankau Slough

PoorPosted for load

Yakutat City and Borough, Alaska · Mile Point 4.6 · Structure no. 1112

Built
1961
64 years old
Condition
Poor
inspected May 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
495 ft
38 main spans
Daily traffic
457
2018 count
Owner
City
City or Municipal Highway Agency

About this bridge

Irr:ocean Cape RD over Ankau Slough is a wood or timber stringer/multi-beam or girder carrying Irr:ocean Cape RD over Ankau Slough in Yakutat City and Borough, Alaska. It was built in 1961, so it is 64 years old, older than the Alaska average of 35.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 457 vehicles a day, roughly 1% of them trucks, projected to reach 500 by 2035. The structure is 495 ft (150.9 m) long and 13 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

CarriesIrr:ocean Cape RD
CrossesAnkau Slough
LocationMile Point 4.6
RouteFederal Lands Road NSP00
StateAlaska
Coordinates59.54584, -139.82382
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating26.2 US tons
Inventory rating18.3 US tons

Structure

MaterialWood or Timber
DeckWood or timber
Main spans38
Design loadHS 15
Structure length495 ft (150.9 m)
Longest span13 ft (4 m)
Deck width13 ft (4 m)
Roadway width12 ft (3.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic457 (2018)
Projected traffic500 by 2035
Trucks1%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Irr:ocean Cape RD over Ankau Slough built?

It was built in 1961, making it 64 years old in 2025.

What condition is Irr:ocean Cape RD over Ankau Slough in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in May 2024.

How much traffic does Irr:ocean Cape RD over Ankau Slough carry?

About 457 vehicles per day (2018 count), of which roughly 1% are trucks.

How long is Irr:ocean Cape RD over Ankau Slough?

The structure is 495 ft (150.9 m) long with a longest span of 13 ft (4 m) and a deck 13 ft wide.

Who owns Irr:ocean Cape RD over Ankau Slough?

It is owned by the City or Municipal Highway Agency.