US Bridges

Wildhorse Road over Wildhorse River

PoorPosted for load

Adams County, Idaho · 9.3 S. 4.7 W. Bear · Structure no. 000000000026565

Built
1908
117 years old, rebuilt 2009
Condition
Poor
inspected September 2024
Type
Truss - Thru
Steel
Length
48 ft
1 main span
Daily traffic
30
2023 count
Owner
County
County Highway Agency

About this bridge

Wildhorse Road over Wildhorse River is a steel truss - thru carrying Wildhorse Road over Wildhorse River in Adams County, Idaho. It was built in 1908 and reconstructed in 2009, so it is 117 years old, older than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 30 vehicles a day, roughly 50% of them trucks, projected to reach 45 by 2042. The structure is 48 ft (14.6 m) long and 18 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

CarriesWildhorse Road
CrossesWildhorse River
Location9.3 S. 4.7 W. Bear
RouteCounty Highway 0
StateIdaho
Coordinates44.89217, -116.76922
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating10 US tons
Inventory rating6 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadH 10
Structure length48 ft (14.6 m)
Longest span46 ft (14 m)
Deck width18 ft (5.5 m)
Roadway width15 ft (4.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2023)
Projected traffic45 by 2042
Trucks50%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$492,000 (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Wildhorse Road over Wildhorse River built?

It was built in 1908, making it 117 years old in 2025. It was reconstructed in 2009.

What condition is Wildhorse Road over Wildhorse River in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in September 2024.

How much traffic does Wildhorse Road over Wildhorse River carry?

About 30 vehicles per day (2023 count), of which roughly 50% are trucks.

How long is Wildhorse Road over Wildhorse River?

The structure is 48 ft (14.6 m) long with a longest span of 46 ft (14 m) and a deck 18 ft wide.

Who owns Wildhorse Road over Wildhorse River?

It is owned by the County Highway Agency.