US 12 over Powder River
FairCuster County, Montana · 26M E Miles City · Structure no. P00002031+07241
- Built
- 1973
- 52 years old
- Condition
- Fair
- inspected April 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 622 ft
- 5 main spans
- Daily traffic
- 552
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
US 12 over Powder River is a prestressed concrete stringer/multi-beam or girder carrying US 12 over Powder River in Custer County, Montana. It was built in 1973, so it is 52 years old, older than the Montana average of 47 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 552 vehicles a day, roughly 11% of them trucks, projected to reach 580 by 2043. The structure is 622 ft (189.6 m) long and 40 ft wide. If it were closed, the detour would be 123.7 mi (199 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was US 12 over Powder River built?
It was built in 1973, making it 52 years old in 2025.
What condition is US 12 over Powder River in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in April 2023.
How much traffic does US 12 over Powder River carry?
About 552 vehicles per day (2023 count), of which roughly 11% are trucks.
How long is US 12 over Powder River?
The structure is 622 ft (189.6 m) long with a longest span of 127 ft (38.6 m) and a deck 40 ft wide.
Who owns US 12 over Powder River?
It is owned by the State Highway Agency.