I 15 over Red Rock River
FairBeaverhead County, Montana · 6.2M S Clark Canyon Dam · Structure no. I00015038+04301
- Built
- 1962
- 63 years old
- Condition
- Fair
- inspected November 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 143 ft
- 3 main spans
- Daily traffic
- 2,116
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I 15 over Red Rock River is a prestressed concrete stringer/multi-beam or girder carrying I 15 over Red Rock River in Beaverhead County, Montana. It was built in 1962, so it is 63 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 2,116 vehicles a day, roughly 25% of them trucks, projected to reach 2,264 by 2043. The structure is 143 ft (43.6 m) long and 47 ft wide. If it were closed, the detour would be 1.2 mi (2 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was I 15 over Red Rock River built?
It was built in 1962, making it 63 years old in 2025.
What condition is I 15 over Red Rock 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 November 2024.
How much traffic does I 15 over Red Rock River carry?
About 2,116 vehicles per day (2023 count), of which roughly 25% are trucks.
How long is I 15 over Red Rock River?
The structure is 143 ft (43.6 m) long with a longest span of 52 ft (15.8 m) and a deck 47 ft wide.
Who owns I 15 over Red Rock River?
It is owned by the State Highway Agency.