State Route 99 over Keefers Slough
GoodButte County, California · 03-BUT-099-39.69 · Structure no. 12 0026
- Built
- 1951
- 74 years old
- Condition
- Good
- inspected April 2022
- Type
- Slab
- Concrete Continuous
- Length
- 76 ft
- 3 main spans
- Daily traffic
- 14,700
- 2020 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 99 over Keefers Slough is a concrete continuous slab carrying State Route 99 over Keefers Slough in Butte County, California. It was built in 1951, so it is 74 years old, older than the California average of 54.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 14,700 vehicles a day, roughly 12% of them trucks, projected to reach 32,579 by 2040. The structure is 76 ft (23.1 m) long and 42 ft wide. If it were closed, the detour would be 13 mi (21 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| 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 99 over Keefers Slough built?
It was built in 1951, making it 74 years old in 2025.
What condition is State Route 99 over Keefers Slough in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2022.
How much traffic does State Route 99 over Keefers Slough carry?
About 14,700 vehicles per day (2020 count), of which roughly 12% are trucks.
How long is State Route 99 over Keefers Slough?
The structure is 76 ft (23.1 m) long with a longest span of 24 ft (7.3 m) and a deck 42 ft wide.
Who owns State Route 99 over Keefers Slough?
It is owned by the State Highway Agency.