Irr Bia Route 1 over Main Canal
Valley County, Montana · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Irr Bia Route 1 over Main Canal in Valley County, Montana, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1972, making it 53 years old at the 2025 inventory.
- It carries about 1,200 vehicles a day (traffic count year 2024).
- It is one of 16 of the 103 inventoried bridges in Valley County rated good (15.5%); 11 (10.7%) 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.
View this bridge on a map → (48.04517, -105.94131)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 7 | Good condition |
| Superstructure | 8 | Very good condition |
| Substructure | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete tee beam |
| Length | about 41 ft |
| Location | 4.0 Km SE of Oswego |
| NBI structure number | 00000000000C603 |
| Condition class | Good |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Montana department of transportation.
Busiest bridges in Valley County
| 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 |
All bridges nearby: Valley County, MT bridge conditions · every bridge in Valley County · Montana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.