Home › Montana › Ravalli County › Old Darby Rd over Rock Creek 052

Old Darby Rd over Rock Creek 052

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

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

Old Darby Rd over Rock Creek 052 in Ravalli County, Montana, is rated in fair condition in the 2025 National Bridge Inventory (as of August 20, 2026).
Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
It was built in 1918 and reconstructed in 1936, making it 107 years old at the 2025 inventory.
It carries about 100 vehicles a day (traffic count year 2025).
Its listed owner is the county highway agency.
It is one of 77 of the 150 inventoried bridges in Ravalli County rated fair (51.3%); 12 (8.0%) 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	Steel stringer or multi-beam girder
Length	about 61 ft
Location	4M N Darby
NBI structure number	L41703003+05001
Condition class	Fair

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

Bridge	Built	Vehicles/day	Condition
US 93 over Mill Creek	2011	15,852	Good
US 93 over Corvallis Canal	1980	14,714	Good
US 93 over Bitterroot River	2005	14,573	Fair
US 93 over Blodgett Creek	2008	14,573	Fair
US 93 over S Fork Bear Creek	2011	13,924	Fair
US 93 over N Fork Bear Creek	2011	13,924	Good