US Bridges

River Canyon Road over Imnaha River

Fair

Wallowa County, Oregon · 22.6 MI S of HWY 350 · Structure no. 21743 000 00001

Built
2011
14 years old
Condition
Fair
inspected September 2024
Type
Slab
Prestressed Concrete
Length
81 ft
1 main span
Daily traffic
30
2020 count
Owner
County
County Highway Agency

About this bridge

River Canyon Road over Imnaha River is a prestressed concrete slab carrying River Canyon Road over Imnaha River in Wallowa County, Oregon. It was built in 2011, so it is 14 years old, younger 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 30 vehicles a day, projected to reach 35 by 2025. The structure is 81 ft (24.8 m) long and 20 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesRiver Canyon Road
CrossesImnaha River
Location22.6 MI S of HWY 350
RouteCounty Highway 0
CountyWallowa County
StateOregon
Coordinates45.26096, -116.80937
Functional classRural Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
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 alignment6: Equal to present minimum criteria
Operating rating55 US tons
Inventory rating42.5 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHL 93
Structure length81 ft (24.8 m)
Longest span79 ft (24.2 m)
Deck width20 ft (6.1 m)
Roadway width20 ft (6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2020)
Projected traffic35 by 2025
Trucks0%
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 River Canyon Road over Imnaha River built?

It was built in 2011, making it 14 years old in 2025.

What condition is River Canyon Road over Imnaha 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 September 2024.

How much traffic does River Canyon Road over Imnaha River carry?

About 30 vehicles per day (2020 count).

How long is River Canyon Road over Imnaha River?

The structure is 81 ft (24.8 m) long with a longest span of 79 ft (24.2 m) and a deck 20 ft wide.

Who owns River Canyon Road over Imnaha River?

It is owned by the County Highway Agency.