US Bridges

Owyhee Rd. B485 over Owyhee River

Fair

Malheur County, Oregon · 083 M NE Owyhee Dam · Structure no. 45C226084600907

Built
1974
51 years old
Condition
Fair
inspected October 2023
Type
Slab
Prestressed Concrete
Length
219 ft
5 main spans
Daily traffic
404
2020 count
Owner
County
County Highway Agency

About this bridge

Owyhee Rd. B485 over Owyhee River is a prestressed concrete slab carrying Owyhee Rd. B485 over Owyhee River in Malheur County, Oregon. It was built in 1974, so it is 51 years old, older than the Oregon average of 49.9 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 404 vehicles a day, roughly 10% of them trucks, projected to reach 464 by 2025. The structure is 219 ft (66.8 m) long and 28 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesOwyhee Rd. B485
CrossesOwyhee River
Location083 M NE Owyhee Dam
RouteCounty Highway 0B485
CountyMalheur County
StateOregon
Coordinates43.70214, -117.19934
Functional classRural Major 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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to 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 rating67 US tons
Inventory rating40 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckOther
Main spans5
Design loadHS 20
Structure length219 ft (66.8 m)
Longest span56 ft (17.1 m)
Deck width28 ft (8.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic404 (2020)
Projected traffic464 by 2025
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Owyhee Rd. B485 over Owyhee River built?

It was built in 1974, making it 51 years old in 2025.

What condition is Owyhee Rd. B485 over Owyhee 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 October 2023.

How much traffic does Owyhee Rd. B485 over Owyhee River carry?

About 404 vehicles per day (2020 count), of which roughly 10% are trucks.

How long is Owyhee Rd. B485 over Owyhee River?

The structure is 219 ft (66.8 m) long with a longest span of 56 ft (17.1 m) and a deck 28 ft wide.

Who owns Owyhee Rd. B485 over Owyhee River?

It is owned by the County Highway Agency.