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I 90 over Sep Bearmouth Road

Granite County, Montana · rated Good in the 2025 National Bridge Inventory

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

I 90 over Sep Bearmouth Road in Granite County, Montana, 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 1970, making it 55 years old at the 2025 inventory.
It carries about 13,081 vehicles a day (traffic count year 2023).
Its listed owner is the state highway agency.
It is one of 28 of the 73 inventoried bridges in Granite County rated good (38.4%); 9 (12.3%) 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	Prestressed concrete stringer or multi-beam girder
Length	about 119 ft
Location	10.5M W Drummond
NBI structure number	I00090143+06511
Condition class	Good

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

Bridge	Built	Vehicles/day	Condition
I 90 over Harvey Creek	1970	13,081	Good
I 90 over Drainage	1971	13,081	Good
I 90 over Clark Fork River	1970	13,081	Poor
I 90 over Rattler Gulch	1971	13,081	Fair
I 90 over Clark Fork River	1970	11,802	Fair
I 90 over Int Bearmouth	1970	6,541	Fair