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I 15 over Int Trask-lowland Rd

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

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

I 15 over Int Trask-lowland Rd in Jefferson 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 1976, making it 49 years old at the 2025 inventory.
It carries about 1,576 vehicles a day (traffic count year 2023).
Its listed owner is the state highway agency.
It is one of 26 of the 136 inventoried bridges in Jefferson County rated good (19.1%); 7 (5.1%) 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	Prestressed concrete stringer or multi-beam girder
Length	about 127 ft
Location	8M N Butte
NBI structure number	I00015138+06601
Condition class	Good

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

Bridge	Built	Vehicles/day	Condition
I 15 over Prickly Pear Creek	1969	5,987	Fair
I 15 over Prickly Pear Creek	1969	5,987	Fair
S 518 over Int Montana City-i 15	1968	5,885	Good
I 90 over Int Cardwell-s 359	1968	5,599	Fair
I 90 over Int Cardwell-s 359	1968	5,599	Fair
I 90 Eastbound over Boulder River	1968	5,599	Good