Rock Creek Road over Cougar Creek
Granite County, Montana · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Rock Creek Road over Cougar Creek in Granite County, Montana, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 8 (very good condition) on the 0-9 scale.
- It was built in 2008, making it 17 years old at the 2025 inventory.
- It carries about 40 vehicles a day.
- It is one of 28 of the 73 inventoried bridges in Granite County rated good (38.4%); 9 (12.3%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated August 2024, on a 24-month routine inspection cycle.
- 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 → (46.45501, -113.76814)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 8 | 8 | Very good condition |
| Superstructure | 8 | 8 | Very good condition |
| Substructure | 8 | 8 | Very good condition |
Bridge details
| Structure | Prestressed concrete slab |
| Length | about 32 ft |
| Location | T08N R17W S07 |
| NBI structure number | 011606000011429 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | August 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 Granite County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I 90 over Harvey Creek | 1970 | 13,081 | Good |
| I 90 over Drainage | 1971 | 13,081 | Good |
| I 90 over Sep Bearmouth Road | 1970 | 13,081 | Good |
| I 90 over Clark Fork River | 1970 | 13,081 | Poor |
| I 90 over Rattler Gulch | 1971 | 13,081 | Fair |
| I 90 over Clark Fork River | 1970 | 11,802 | Fair |
All bridges nearby: Granite County, MT bridge conditions · every bridge in Granite County · Montana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.