State Route 121 over Yellow Creek
GoodSonoma County, California · 04-SON-121-6.52 · Structure no. 20 0021
- Built
- 1922
- 103 years old
- Condition
- Good
- inspected November 2024
- Type
- Tee Beam
- Concrete
- Length
- 22 ft
- 1 main span
- Daily traffic
- 16,150
- 2014 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 121 over Yellow Creek is a concrete tee beam carrying State Route 121 over Yellow Creek in Sonoma County, California. It was built in 1922, so it is 103 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 16,150 vehicles a day, roughly 8% of them trucks, projected to reach 22,826 by 2046. The structure is 22 ft (6.7 m) long and 29 ft wide. If it were closed, the detour would be 9.9 mi (16 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 | 8 Very Good | No problems noted. |
| 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 121 over Yellow Creek built?
It was built in 1922, making it 103 years old in 2025.
What condition is State Route 121 over Yellow Creek 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 November 2024.
How much traffic does State Route 121 over Yellow Creek carry?
About 16,150 vehicles per day (2014 count), of which roughly 8% are trucks.
How long is State Route 121 over Yellow Creek?
The structure is 22 ft (6.7 m) long with a longest span of 20 ft (6.1 m) and a deck 29 ft wide.
Who owns State Route 121 over Yellow Creek?
It is owned by the State Highway Agency.