3120 N over Big Lost River
FairButte County, Idaho · 0.4 S. 0.3 E. Moore · Structure no. 000000000031495
- Built
- 1979
- 46 years old, rebuilt 1993
- Condition
- Fair
- inspected July 2023
- Type
- Stringer/Multi-beam or Girder
- Steel
- Length
- 47 ft
- 1 main span
- Daily traffic
- 20
- 2023 count
- Owner
- County
- County Highway Agency
About this bridge
3120 N over Big Lost River is a steel stringer/multi-beam or girder carrying 3120 N over Big Lost River in Butte County, Idaho. It was built in 1979 and reconstructed in 1993, so it is 46 years old, older than the Idaho average of 45.3 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 20 vehicles a day, roughly 50% of them trucks, projected to reach 30 by 2042. The structure is 47 ft (14.3 m) long and 24 ft wide. If it were closed, the detour would be 0.6 mi (1 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 | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was 3120 N over Big Lost River built?
It was built in 1979, making it 46 years old in 2025. It was reconstructed in 1993.
What condition is 3120 N over Big Lost 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 3120 N over Big Lost River carry?
About 20 vehicles per day (2023 count), of which roughly 50% are trucks.
How long is 3120 N over Big Lost River?
The structure is 47 ft (14.3 m) long with a longest span of 46 ft (14 m) and a deck 24 ft wide.
Who owns 3120 N over Big Lost River?
It is owned by the County Highway Agency.