State Route 99 over Cat Tail Slough
FairButte County, California · 03-BUT-099-5.34 · Structure no. 12 0001
- Built
- 1910
- 115 years old, rebuilt 1939
- Condition
- Fair
- inspected April 2023
- Type
- Stringer/Multi-beam or Girder
- Concrete
- Length
- 21 ft
- 1 main span
- Daily traffic
- 13,400
- 2020 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 99 over Cat Tail Slough is a concrete stringer/multi-beam or girder carrying State Route 99 over Cat Tail Slough in Butte County, California. It was built in 1910 and reconstructed in 1939, so it is 115 years old, older 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 5 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 13,400 vehicles a day, roughly 10% of them trucks, projected to reach 24,353 by 2041. The structure is 21 ft (6.3 m) long and 38 ft wide. If it were closed, the detour would be 8.1 mi (13 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 | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was State Route 99 over Cat Tail Slough built?
It was built in 1910, making it 115 years old in 2025. It was reconstructed in 1939.
What condition is State Route 99 over Cat Tail Slough 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 99 over Cat Tail Slough carry?
About 13,400 vehicles per day (2020 count), of which roughly 10% are trucks.
How long is State Route 99 over Cat Tail Slough?
The structure is 21 ft (6.3 m) long with a longest span of 19 ft (5.8 m) and a deck 38 ft wide.
Who owns State Route 99 over Cat Tail Slough?
It is owned by the State Highway Agency.