US Bridges

Elk Prairie Road over North Fork Willapa River

GoodPosted for load

Pacific County, Washington · 18.3 SE JCT US 101 · Structure no. 081427000000000

Built
1964
61 years old
Condition
Good
inspected June 2024
Type
Slab
Concrete Continuous
Length
100 ft
3 main spans
Daily traffic
44
2023 count
Owner
County
County Highway Agency

About this bridge

Elk Prairie Road over North Fork Willapa River is a concrete continuous slab carrying Elk Prairie Road over North Fork Willapa River in Pacific County, Washington. It was built in 1964, so it is 61 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. Its operating status is: posted for load restriction.

It carries about 44 vehicles a day, roughly 1% of them trucks, projected to reach 66 by 2043. The structure is 100 ft (30.5 m) long and 26 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

CarriesElk Prairie Road
CrossesNorth Fork Willapa River
Location18.3 SE JCT US 101
RouteCounty Highway 94700
Coordinates46.53236, -123.49503
Functional classRural Minor Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating29 US tons
Inventory rating20.9 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length100 ft (30.5 m)
Longest span40 ft (12.2 m)
Deck width26 ft (8 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic44 (2023)
Projected traffic66 by 2043
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$1.5 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Elk Prairie Road over North Fork Willapa River built?

It was built in 1964, making it 61 years old in 2025.

What condition is Elk Prairie Road over North Fork Willapa River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in June 2024.

How much traffic does Elk Prairie Road over North Fork Willapa River carry?

About 44 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is Elk Prairie Road over North Fork Willapa River?

The structure is 100 ft (30.5 m) long with a longest span of 40 ft (12.2 m) and a deck 26 ft wide.

Who owns Elk Prairie Road over North Fork Willapa River?

It is owned by the County Highway Agency.