US Bridges

SR 20 over Okanogan River

Fair

Okanogan County, Washington · 0.2 E JCT SR 215 · Structure no. 0005956A0000000

Built
1959
66 years old
Condition
Fair
inspected March 2023
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
368 ft
6 main spans
Daily traffic
2,479
2023 count
Owner
State
State Highway Agency

About this bridge

SR 20 over Okanogan River is a concrete continuous box beam or girders - multiple carrying SR 20 over Okanogan River in Okanogan County, Washington. It was built in 1959, so it is 66 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 2,479 vehicles a day, roughly 6% of them trucks, projected to reach 2,866 by 2039. The structure is 368 ft (112.2 m) long and 32 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSR 20
CrossesOkanogan River
Location0.2 E JCT SR 215
RouteState Highway 20
CountyOkanogan County
StateWashington
Coordinates48.35374, -119.59374
Functional classRural Minor Arterial

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 protection7 GoodSome minor problems.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating99 US tons
Inventory rating61 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length368 ft (112.2 m)
Longest span89 ft (27.1 m)
Deck width32 ft (9.9 m)
Roadway width30 ft (9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,479 (2023)
Projected traffic2,866 by 2039
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

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$5.9 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 20 over Okanogan River built?

It was built in 1959, making it 66 years old in 2025.

What condition is SR 20 over Okanogan River 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 March 2023.

How much traffic does SR 20 over Okanogan River carry?

About 2,479 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is SR 20 over Okanogan River?

The structure is 368 ft (112.2 m) long with a longest span of 89 ft (27.1 m) and a deck 32 ft wide.

Who owns SR 20 over Okanogan River?

It is owned by the State Highway Agency.