IRR - S 313 over Rotten Grass Creek
FairBig Horn County, Montana · Saint Xavier · Structure no. S00313023+08091
- Built
- 1983
- 42 years old
- Condition
- Fair
- inspected November 2023
- Type
- Slab
- Concrete Continuous
- Length
- 60 ft
- 3 main spans
- Daily traffic
- 621
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
IRR - S 313 over Rotten Grass Creek is a concrete continuous slab carrying IRR - S 313 over Rotten Grass Creek in Big Horn County, Montana. It was built in 1983, so it is 42 years old, younger 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 621 vehicles a day, roughly 7% of them trucks, projected to reach 652 by 2043. The structure is 60 ft (18.3 m) long and 30 ft wide. If it were closed, the detour would be 80.2 mi (129 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 | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was IRR - S 313 over Rotten Grass Creek built?
It was built in 1983, making it 42 years old in 2025.
What condition is IRR - S 313 over Rotten Grass Creek 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 2023.
How much traffic does IRR - S 313 over Rotten Grass Creek carry?
About 621 vehicles per day (2023 count), of which roughly 7% are trucks.
How long is IRR - S 313 over Rotten Grass Creek?
The structure is 60 ft (18.3 m) long with a longest span of 23 ft (7 m) and a deck 30 ft wide.
Who owns IRR - S 313 over Rotten Grass Creek?
It is owned by the State Highway Agency.