US Bridges

SR 4 over W Fk Skamokawa CR

Fair

Wahkiakum County, Washington · 22.7 E JCT SR 401 · Structure no. 0002330A0000000

Built
1938
87 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
70 ft
4 main spans
Daily traffic
1,255
2023 count
Owner
State
State Highway Agency

About this bridge

SR 4 over W Fk Skamokawa CR is a wood or timber stringer/multi-beam or girder carrying SR 4 over W Fk Skamokawa CR in Wahkiakum County, Washington. It was built in 1938, so it is 87 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 1,255 vehicles a day, roughly 13% of them trucks, projected to reach 1,478 by 2039. The structure is 70 ft (21.3 m) long and 31 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesSR 4
CrossesW Fk Skamokawa CR
Location22.7 E JCT SR 401
RouteState Highway 4
CountyWahkiakum County
StateWashington
Coordinates46.28928, -123.46722
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56 US tons
Inventory rating40 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length70 ft (21.3 m)
Longest span17 ft (5.2 m)
Deck width31 ft (9.3 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,255 (2023)
Projected traffic1,478 by 2039
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$1.1 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 4 over W Fk Skamokawa CR built?

It was built in 1938, making it 87 years old in 2025.

What condition is SR 4 over W Fk Skamokawa CR in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in April 2024.

How much traffic does SR 4 over W Fk Skamokawa CR carry?

About 1,255 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is SR 4 over W Fk Skamokawa CR?

The structure is 70 ft (21.3 m) long with a longest span of 17 ft (5.2 m) and a deck 31 ft wide.

Who owns SR 4 over W Fk Skamokawa CR?

It is owned by the State Highway Agency.