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Irr Bia Rte 30 over Main Canal

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

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

Irr Bia Rte 30 over Main Canal in Valley 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 6 (satisfactory condition) on the 0-9 scale.
It was built in 1983, making it 42 years old at the 2025 inventory.
It carries about 225 vehicles a day (traffic count year 2024).
It is one of 76 of the 103 inventoried bridges in Valley County rated fair (73.8%); 11 (10.7%) 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	Prestressed concrete stringer or multi-beam girder
Length	about 47 ft
Location	8.9 Km SW of Oswego
NBI structure number	00000000000C618
Condition class	Fair

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

Bridge	Built	Vehicles/day	Condition
US 2 over Cherry Creek Overflow	1980	5,857	Fair
US 2 over Cherry Creek	1979	5,857	Fair
US 2 over Goudge Coulee	1994	1,967	Fair
US 2 over Whately Creek	1987	1,967	Fair
US 2 over Porcupine Creek	2006	1,584	Fair
US 2 over Porcupine Creek Overflow	2006	1,584	Fair