US Bridges

Back Road over Wimpey Creek

Good

Lemhi County, Idaho · 10.4 SE Salmon · Structure no. 000000000032708

Built
2013
12 years old
Condition
Good
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
44 ft
1 main span
Daily traffic
50
2023 count
Owner
County
County Highway Agency

About this bridge

Back Road over Wimpey Creek is a steel stringer/multi-beam or girder carrying Back Road over Wimpey Creek in Lemhi County, Idaho. It was built in 2013, so it is 12 years old, younger than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 50 vehicles a day, roughly 25% of them trucks, projected to reach 75 by 2042. The structure is 44 ft (13.4 m) long and 29 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesBack Road
CrossesWimpey Creek
Location10.4 SE Salmon
RouteCounty Highway 0
CountyLemhi County
StateIdaho
Coordinates45.09781, -113.72011
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating48.6 US tons
Inventory rating37.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadHL 93
Structure length44 ft (13.4 m)
Longest span42 ft (12.8 m)
Deck width29 ft (8.8 m)
Roadway width28 ft (8.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2023)
Projected traffic75 by 2042
Trucks25%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Back Road over Wimpey Creek built?

It was built in 2013, making it 12 years old in 2025.

What condition is Back Road over Wimpey Creek 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 April 2024.

How much traffic does Back Road over Wimpey Creek carry?

About 50 vehicles per day (2023 count), of which roughly 25% are trucks.

How long is Back Road over Wimpey Creek?

The structure is 44 ft (13.4 m) long with a longest span of 42 ft (12.8 m) and a deck 29 ft wide.

Who owns Back Road over Wimpey Creek?

It is owned by the County Highway Agency.