State Route 161 over Lost River
FairSiskiyou County, California · 02-SIS-161-19.18 · Structure no. 02 0198
- Built
- 2008
- 17 years old
- Condition
- Fair
- inspected April 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete Continuous
- Length
- 261 ft
- 3 main spans
- Daily traffic
- 655
- 2015 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 161 over Lost River is a prestressed concrete continuous stringer/multi-beam or girder carrying State Route 161 over Lost River in Siskiyou County, California. It was built in 2008, so it is 17 years old, younger than the California average of 54.8 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 655 vehicles a day, roughly 12% of them trucks, projected to reach 796 by 2040. The structure is 261 ft (79.6 m) long and 42 ft wide. If it were closed, the detour would be 16.2 mi (26 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 | 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 State Route 161 over Lost River built?
It was built in 2008, making it 17 years old in 2025.
What condition is State Route 161 over 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 April 2023.
How much traffic does State Route 161 over Lost River carry?
About 655 vehicles per day (2015 count), of which roughly 12% are trucks.
How long is State Route 161 over Lost River?
The structure is 261 ft (79.6 m) long with a longest span of 95 ft (29 m) and a deck 42 ft wide.
Who owns State Route 161 over Lost River?
It is owned by the State Highway Agency.