US Bridges

Bayhorse Road over Salmon River;bayhorse CR

FairPosted for load

Custer County, Idaho · 8.5 S. 1.2 W. Challis · Structure no. 000000000031660

Built
1930
95 years old
Condition
Fair
inspected October 2023
Type
Truss - Thru
Steel
Length
122 ft
1 main span
Daily traffic
170
2023 count
Owner
County
County Highway Agency

About this bridge

Bayhorse Road over Salmon River;bayhorse CR is a steel truss - thru carrying Bayhorse Road over Salmon River;bayhorse CR in Custer County, Idaho. It was built in 1930, so it is 95 years old, older than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.

It carries about 170 vehicles a day, roughly 5% of them trucks, projected to reach 255 by 2039. The structure is 122 ft (37.2 m) long and 16 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesBayhorse Road
CrossesSalmon River;bayhorse CR
Location8.5 S. 1.2 W. Challis
RouteCounty Highway 0
CountyCuster County
StateIdaho
Coordinates44.37797, -114.25622
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating8 US tons
Inventory rating4 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckWood or timber
Main spans1
Design loadH 10
Structure length122 ft (37.2 m)
Longest span120 ft (36.6 m)
Deck width16 ft (4.9 m)
Roadway width16 ft (4.8 m)
Vertical clearance over deck15 ft (4.4 m)

Traffic and service

Average daily traffic170 (2023)
Projected traffic255 by 2039
Trucks5%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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$1.1 million (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Bayhorse Road over Salmon River;bayhorse CR built?

It was built in 1930, making it 95 years old in 2025.

What condition is Bayhorse Road over Salmon River;bayhorse CR 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 Bayhorse Road over Salmon River;bayhorse CR carry?

About 170 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is Bayhorse Road over Salmon River;bayhorse CR?

The structure is 122 ft (37.2 m) long with a longest span of 120 ft (36.6 m) and a deck 16 ft wide.

Who owns Bayhorse Road over Salmon River;bayhorse CR?

It is owned by the County Highway Agency.