US Highway 101 over Mark West Creek
FairSonoma County, California · 04-SON-101-26.10 · Structure no. 20 0180
- Built
- 1962
- 63 years old, rebuilt 2013
- Condition
- Fair
- inspected August 2024
- Type
- Slab
- Concrete Continuous
- Length
- 146 ft
- 5 main spans
- Daily traffic
- 62,000
- 2012 count
- Owner
- State
- State Highway Agency
About this bridge
US Highway 101 over Mark West Creek is a concrete continuous slab carrying US Highway 101 over Mark West Creek in Sonoma County, California. It was built in 1962 and reconstructed in 2013, so it is 63 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 62,000 vehicles a day, roughly 6% of them trucks, projected to reach 145,347 by 2046. The structure is 146 ft (44.5 m) long and 164 ft wide. If it were closed, the detour would be 1.2 mi (2 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was US Highway 101 over Mark West Creek built?
It was built in 1962, making it 63 years old in 2025. It was reconstructed in 2013.
What condition is US Highway 101 over Mark West Creek 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 August 2024.
How much traffic does US Highway 101 over Mark West Creek carry?
About 62,000 vehicles per day (2012 count), of which roughly 6% are trucks.
How long is US Highway 101 over Mark West Creek?
The structure is 146 ft (44.5 m) long with a longest span of 32 ft (9.8 m) and a deck 164 ft wide.
Who owns US Highway 101 over Mark West Creek?
It is owned by the State Highway Agency.