Home › Montana › Mineral County › I 90 EB over St. Regis River

I 90 EB over St. Regis River

Mineral County, Montana · rated Fair in the 2025 National Bridge Inventory

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

I 90 EB over St. Regis River in Mineral County, Montana, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the substructure, rated 6 (satisfactory condition) on the 0-9 scale.
It was built in 1981, making it 44 years old at the 2025 inventory.
It carries about 4,056 vehicles a day (traffic count year 2023).
Its listed owner is the state highway agency.
It is one of 99 of the 153 inventoried bridges in Mineral County rated fair (64.7%); 17 (11.1%) are rated poor.
A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.

Component ratings


Structure	Prestressed concrete stringer or multi-beam girder
Length	about 212 ft
Location	1.9M W St. Regis
NBI structure number	I00090031+04741
Condition class	Fair

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

Bridge	Built	Vehicles/day	Condition
I 90 over Drainage	1986	8,111	Good
I 90 over Sep Local Road	1973	7,824	Fair
I 90 over Sep Local Road	1973	7,824	Fair
I 90 over Int Taft	1973	7,824	Fair
I 90 over Sep Randolph Creek Road	1973	7,824	Fair
I 90 over St. Regis River	1973	7,824	Fair