US Bridges

SH 75 over Salmon River;slate CR Br

Good

Custer County, Idaho · 9.0 W. Clayton · Structure no. 000000000017786

Built
2011
14 years old
Condition
Good
inspected July 2022
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
451 ft
3 main spans
Daily traffic
680
2023 count
Owner
State
State Highway Agency

About this bridge

SH 75 over Salmon River;slate CR Br is a steel continuous stringer/multi-beam or girder carrying SH 75 over Salmon River;slate CR Br in Custer County, Idaho. It was built in 2011, so it is 14 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 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 680 vehicles a day, roughly 15% of them trucks, projected to reach 1,020 by 2042. The structure is 451 ft (137.5 m) long and 40 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesSH 75
CrossesSalmon River;slate CR Br
Location9.0 W. Clayton
RouteState Highway 75
CountyCuster County
StateIdaho
Coordinates44.25389, -114.55306
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
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56 US tons
Inventory rating33 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length451 ft (137.5 m)
Longest span256 ft (78 m)
Deck width40 ft (12.1 m)
Roadway width37 ft (11.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic680 (2023)
Projected traffic1,020 by 2042
Trucks15%
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 Salmon River;slate CR Br built?

It was built in 2011, making it 14 years old in 2025.

What condition is SH 75 over Salmon River;slate CR Br 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 July 2022.

How much traffic does SH 75 over Salmon River;slate CR Br carry?

About 680 vehicles per day (2023 count), of which roughly 15% are trucks.

How long is SH 75 over Salmon River;slate CR Br?

The structure is 451 ft (137.5 m) long with a longest span of 256 ft (78 m) and a deck 40 ft wide.

Who owns SH 75 over Salmon River;slate CR Br?

It is owned by the State Highway Agency.