Irr - US 87 over School Section Coulee
Chouteau County, Montana · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Irr - US 87 over School Section Coulee in Chouteau County, Montana, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 7 (good condition) on the 0-9 scale.
- It was built in 1970, making it 55 years old at the 2025 inventory.
- It carries about 1,694 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 25 of the 43 inventoried bridges in Chouteau County rated good (58.1%); 2 (4.7%) 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 → (48.24522, -110.05703)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 7 | Good condition |
Bridge details
| Structure | Steel culvert |
| Length | about 23 ft |
| Location | 4M N Big Sandy |
| NBI structure number | 000000000008092 |
| Condition class | Good |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Montana department of transportation.
Busiest bridges in Chouteau County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 87 over Abandoned Railroad | 1974 | 1,727 | Fair |
| Irr - US 87 over Big Sandy Creek | 1990 | 1,694 | Good |
| US 87 over Marias River | 1988 | 1,417 | Good |
| S 80-13th St over Missouri River | 1962 | 930 | Poor |
| S 80 over RR | 1953 | 849 | Fair |
| S 80 over Shonkin Creek | 2003 | 696 | Good |
All bridges nearby: Chouteau County, MT bridge conditions · every bridge in Chouteau County · Montana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.