S 484 Fh 51 over Otter Creek
Powder River County, Montana · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- S 484 Fh 51 over Otter Creek in Powder River County, Montana, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1999, making it 26 years old at the 2025 inventory.
- It carries about 35 vehicles a day (traffic count year 2023).
- Its listed owner is the county highway agency.
- It is one of 11 of the 23 inventoried bridges in Powder River County rated fair (47.8%); 0 (0.0%) 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 September 2023, 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 → (45.24933, -106.16189)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 8 | 8 | Very good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 123 ft |
| Location | 27M SE Ashland |
| NBI structure number | S00484023+02001 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | September 2023 |
| 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 Powder River County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 212 over Little Powder River | 1976 | 2,594 | Fair |
| US 212 over E Fk Little Powder River | 1983 | 2,594 | Fair |
| US 212 over E Fork Otter Creek | 1992 | 2,305 | Good |
| US 212 over Pumpkin Creek | 2012 | 2,197 | Good |
| US 212 over Powder River | 1985 | 2,084 | Good |
| S 59 over Mizpah Creek | 2001 | 742 | Good |
All bridges nearby: Powder River County, MT bridge conditions · every bridge in Powder River County · Montana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.