Home › Idaho › Custer County › US 93 over Salmon River;challis Br.

US 93 over Salmon River;challis Br.

Custer County, Idaho · rated Good in the 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

US 93 over Salmon River;challis Br. in Custer County, Idaho, is rated in good condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
It was built in 1995, making it 30 years old at the 2025 inventory.
It carries about 1,400 vehicles a day (traffic count year 2023).
Its listed owner is the state highway agency.
It is one of 40 of the 126 inventoried bridges in Custer County rated good (31.7%); 14 (11.1%) are rated poor.
A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.

Component ratings


Structure	Continuous steel stringer or multi-beam girder
Length	about 306 ft
Location	2.6 S. Challis
NBI structure number	000000000018031
Condition class	Good

Source: FHWA National Bridge Inventory, 2025 data as reported by the Idaho department of transportation.

Bridge	Built	Vehicles/day	Condition
US 93 over Garden Creek	1941	2,300	Fair
SH 21 over Crooked Creek	1968	2,200	Fair
US 93 over Big Lost River	1987	1,500	Fair
US 93 over Challis Creek	1991	1,400	Good
Capitol Avenue over Swauger Slough	1940	1,220	Fair
SH 75 over Redfish Lake Creek	1960	1,100	Fair