I 15 over RR

Lewis and Clark County, Montana · rated Good in the 2025 National Bridge Inventory

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

I 15 over RR in Lewis and Clark 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 1967, making it 58 years old at the 2025 inventory.
It carries about 2,201 vehicles a day (traffic count year 2023).
Its listed owner is the state highway agency.
It is one of 118 of the 204 inventoried bridges in Lewis and Clark County rated good (57.8%); 11 (5.4%) 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 365 ft
Location	2M N Craig
NBI structure number	I00015235+09782
Condition class	Good

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

Bridge	Built	Vehicles/day	Condition
Lyndale Ave-us 12 over Great Northern Area	2003	20,397	Good
US 12 over RR	1978	19,327	Good
N Last Chance Gulc over RR	2003	18,569	Good
E Custer Ave over Int Custer Ave-i 15	2012	16,988	Good
US 12 over Prickly Pear Creek	1978	15,333	Good
I 15 over Sep Boulder Ave-rr	2016	14,810	Fair