US Bridges

School Flat Road over Wallowa River

Good

Wallowa County, Oregon · 0.3 MI E of Jimtown Road · Structure no. 18533 05340 025

Built
1999
26 years old
Condition
Good
inspected September 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
93 ft
1 main span
Daily traffic
99
2020 count
Owner
County
County Highway Agency

About this bridge

School Flat Road over Wallowa River is a prestressed concrete box beam or girders - multiple carrying School Flat Road over Wallowa River in Wallowa County, Oregon. It was built in 1999, so it is 26 years old, younger than the Oregon average of 49.9 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.

It carries about 99 vehicles a day, roughly 1% of them trucks, projected to reach 119 by 2025. The structure is 93 ft (28.3 m) long and 29 ft wide. If it were closed, the detour would be 14.3 mi (23 km).

CarriesSchool Flat Road
CrossesWallowa River
Location0.3 MI E of Jimtown Road
RouteCounty Highway 0
StateOregon
Coordinates45.5018, -117.415
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 inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation7: Better than 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 rating54.7 US tons
Inventory rating42.1 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 25 or greater
Structure length93 ft (28.3 m)
Longest span91 ft (27.7 m)
Deck width29 ft (8.8 m)
Roadway width25 ft (7.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic99 (2020)
Projected traffic119 by 2025
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.3 mi (23 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 School Flat Road over Wallowa River built?

It was built in 1999, making it 26 years old in 2025.

What condition is School Flat Road over Wallowa 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 September 2023.

How much traffic does School Flat Road over Wallowa River carry?

About 99 vehicles per day (2020 count), of which roughly 1% are trucks.

How long is School Flat Road over Wallowa River?

The structure is 93 ft (28.3 m) long with a longest span of 91 ft (27.7 m) and a deck 29 ft wide.

Who owns School Flat Road over Wallowa River?

It is owned by the County Highway Agency.