US Bridges

County Road 4015 over Sinlahekin Creek

FairPosted for load

Okanogan County, Washington · 3.1 S.9425@ Loomis · Structure no. 081809000000000

Built
1973
52 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
30 ft
1 main span
Daily traffic
56
2022 count
Owner
County
County Highway Agency

About this bridge

County Road 4015 over Sinlahekin Creek is a prestressed concrete stringer/multi-beam or girder carrying County Road 4015 over Sinlahekin Creek in Okanogan County, Washington. It was built in 1973, so it is 52 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 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.

It carries about 56 vehicles a day, roughly 14% of them trucks, projected to reach 100 by 2042. The structure is 30 ft (9.2 m) long and 28 ft wide. If it were closed, the detour would be 39.8 mi (64 km).

Location

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CarriesCounty Road 4015
CrossesSinlahekin Creek
Location3.1 S.9425@ Loomis
RouteCounty Highway 40150
CountyOkanogan County
StateWashington
Coordinates48.78433, -119.64939
Functional classRural Minor Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating34.6 US tons
Inventory rating26.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length30 ft (9.2 m)
Longest span29 ft (8.7 m)
Deck width28 ft (8.5 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic56 (2022)
Projected traffic100 by 2042
Trucks14%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed39.8 mi (64 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.5 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County Road 4015 over Sinlahekin Creek built?

It was built in 1973, making it 52 years old in 2025.

What condition is County Road 4015 over Sinlahekin Creek 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 September 2024.

How much traffic does County Road 4015 over Sinlahekin Creek carry?

About 56 vehicles per day (2022 count), of which roughly 14% are trucks.

How long is County Road 4015 over Sinlahekin Creek?

The structure is 30 ft (9.2 m) long with a longest span of 29 ft (8.7 m) and a deck 28 ft wide.

Who owns County Road 4015 over Sinlahekin Creek?

It is owned by the County Highway Agency.