US 87 over Drainage
Fergus County, Montana · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 87 over Drainage in Fergus County, Montana, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1939, making it 86 years old at the 2025 inventory.
- It carries about 1,067 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 97 of the 158 inventoried bridges in Fergus County rated fair (61.4%); 9 (5.7%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (fair), but component ratings moved: deck 6 to 7, superstructure 5 to 6.
- Its most recent inspection on record is dated October 2024, on a 24-month routine inspection cycle.
- 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.
View this bridge on a map → (47.0451, -108.84304)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 7 | Good condition |
| Superstructure | 5 | 6 | Satisfactory condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Timber stringer or multi-beam girder |
| Length | about 25 ft |
| Location | 2M NW Grass Range |
| NBI structure number | P00057111+00731 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Montana department of transportation.
Busiest bridges in Fergus County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 87-e Main St over Mill Ditch | 1922 | 8,747 | Fair |
| US 87-w Main St over Big Spring Creek | 1962 | 5,357 | Fair |
| US 191-1st Ave N over Big Spring Creek | 1960 | 5,189 | Fair |
| US 87 over Boyd Creek | 1942 | 2,831 | Fair |
| US 191-kendall Rd over Big Spring Creek | 1976 | 2,663 | Fair |
| US 87 over Beaver Creek | 2009 | 2,589 | Good |
All bridges nearby: Fergus County, MT bridge conditions · every bridge in Fergus County · Montana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.