US 93 over Big Lost River
FairCuster County, Idaho · 10.3 S. Mackay · Structure no. 000000000017995
- Built
- 1987
- 38 years old
- Condition
- Fair
- inspected October 2023
- Type
- Box Beam or Girders - Multiple
- Prestressed Concrete
- Length
- 65 ft
- 1 main span
- Daily traffic
- 1,500
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
US 93 over Big Lost River is a prestressed concrete box beam or girders - multiple carrying US 93 over Big Lost River in Custer County, Idaho. It was built in 1987, so it is 38 years old, younger 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 1,500 vehicles a day, roughly 20% of them trucks, projected to reach 2,250 by 2042. The structure is 65 ft (19.8 m) long and 40 ft wide. If it were closed, the detour would be 98.8 mi (159 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was US 93 over Big Lost River built?
It was built in 1987, making it 38 years old in 2025.
What condition is US 93 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 October 2023.
How much traffic does US 93 over Big Lost River carry?
About 1,500 vehicles per day (2023 count), of which roughly 20% are trucks.
How long is US 93 over Big Lost River?
The structure is 65 ft (19.8 m) long with a longest span of 63 ft (19.2 m) and a deck 40 ft wide.
Who owns US 93 over Big Lost River?
It is owned by the State Highway Agency.