Home › Montana › Petroleum County › S 500 over North Willow Creek

S 500 over North Willow Creek

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

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

S 500 over North Willow Creek in Petroleum 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 1975, making it 50 years old at the 2025 inventory.
It carries about 33 vehicles a day (traffic count year 2023).
Its listed owner is the county highway agency.
It is one of 8 of the 26 inventoried bridges in Petroleum County rated good (30.8%); 4 (15.4%) 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 118 ft
Location	13M SW Mosby
NBI structure number	S00500023+00001
Condition class	Good

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

Bridge	Built	Vehicles/day	Condition
S 200 over Box Elder Creek	1953	539	Fair
S 244 over Mcdonald Creek	1941	245	Fair
S 244 over Pike Creek	1939	233	Fair
S 244 over Drainage	1935	233	Fair
S 244 over Yellow Water Cr-elk CR	1948	233	Poor
S 244 over Drainage	1940	208	Fair