US Bridges

SH 75 over E. Fk. Salmon River

Good

Custer County, Idaho · 5.1 E. Clayton · Structure no. 000000000017801

Built
2014
11 years old
Condition
Good
inspected October 2022
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
140 ft
1 main span
Daily traffic
600
2023 count
Owner
State
State Highway Agency

About this bridge

SH 75 over E. Fk. Salmon River is a prestressed concrete stringer/multi-beam or girder carrying SH 75 over E. Fk. Salmon River in Custer County, Idaho. It was built in 2014, so it is 11 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 600 vehicles a day, roughly 18% of them trucks, projected to reach 900 by 2042. The structure is 140 ft (42.7 m) long and 44 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

CarriesSH 75
CrossesE. Fk. Salmon River
Location5.1 E. Clayton
RouteState Highway 75
StateIdaho
Coordinates44.26728, -114.32586
Functional classRural Minor Arterial

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 protection9 ExcellentNo problems noted.
Last inspectionOctober 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry8: Equal to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating75.4 US tons
Inventory rating38.6 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHL 93
Structure length140 ft (42.7 m)
Longest span137 ft (41.8 m)
Deck width44 ft (13.3 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic600 (2023)
Projected traffic900 by 2042
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 SH 75 over E. Fk. Salmon River built?

It was built in 2014, making it 11 years old in 2025.

What condition is SH 75 over E. Fk. Salmon 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 October 2022.

How much traffic does SH 75 over E. Fk. Salmon River carry?

About 600 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is SH 75 over E. Fk. Salmon River?

The structure is 140 ft (42.7 m) long with a longest span of 137 ft (41.8 m) and a deck 44 ft wide.

Who owns SH 75 over E. Fk. Salmon River?

It is owned by the State Highway Agency.