State Route 99 over Biggs Extension Canal
FairButte County, California · 03-BUT-099-9.21 · Structure no. 12 0004
- Built
- 1921
- 104 years old, rebuilt 1950
- Condition
- Fair
- inspected April 2023
- Type
- Tee Beam
- Concrete Continuous
- Length
- 36 ft
- 2 main spans
- Daily traffic
- 11,050
- 2020 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 99 over Biggs Extension Canal is a concrete continuous tee beam carrying State Route 99 over Biggs Extension Canal in Butte County, California. It was built in 1921 and reconstructed in 1950, so it is 104 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 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 11,050 vehicles a day, roughly 10% of them trucks, projected to reach 21,231 by 2041. The structure is 36 ft (11.1 m) long and 42 ft wide. If it were closed, the detour would be 6.2 mi (10 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 | 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 Biggs Extension Canal built?
It was built in 1921, making it 104 years old in 2025. It was reconstructed in 1950.
What condition is State Route 99 over Biggs Extension Canal 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 Biggs Extension Canal carry?
About 11,050 vehicles per day (2020 count), of which roughly 10% are trucks.
How long is State Route 99 over Biggs Extension Canal?
The structure is 36 ft (11.1 m) long with a longest span of 17 ft (5.2 m) and a deck 42 ft wide.
Who owns State Route 99 over Biggs Extension Canal?
It is owned by the State Highway Agency.