300-1 over ST Regis River
FairMineral County, Montana · ST Regis River · Structure no. 011607000001052
- Built
- 1955
- 70 years old
- Condition
- Fair
- inspected July 2023
- Type
- Girder and Floorbeam System
- Steel
- Length
- 125 ft
- 2 main spans
- Daily traffic
- 50
- Owner
- Federal
- U.S. Forest Service
About this bridge
300-1 over ST Regis River is a steel girder and floorbeam system carrying 300-1 over ST Regis River in Mineral County, Montana. It was built in 1955, so it is 70 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 5 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 125 ft (38 m) long and 18 ft wide. If it were closed, the detour would be 98.2 mi (158 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 | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| 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 300-1 over ST Regis River built?
It was built in 1955, making it 70 years old in 2025.
What condition is 300-1 over ST Regis 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 July 2023.
How much traffic does 300-1 over ST Regis River carry?
About 50 vehicles per day (latest count).
How long is 300-1 over ST Regis River?
The structure is 125 ft (38 m) long with a longest span of 58 ft (17.8 m) and a deck 18 ft wide.
Who owns 300-1 over ST Regis River?
It is owned by the U.S. Forest Service and maintained by the Private (other than railroad).