River RD over Mark West Creek
PoorSonoma County, California · 11.2 MI W of SR 116 · Structure no. 20C0157
- Built
- 1958
- 67 years old
- Condition
- Poor
- inspected February 2025
- Type
- Tee Beam
- Concrete Continuous
- Length
- 234 ft
- 3 main spans
- Daily traffic
- 8,000
- 2018 count
- Owner
- County
- County Highway Agency
About this bridge
River RD over Mark West Creek is a concrete continuous tee beam carrying River RD over Mark West Creek in Sonoma County, California. It was built in 1958, so it is 67 years old, older than the California average of 54.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
It carries about 8,000 vehicles a day, roughly 2% of them trucks, projected to reach 11,136 by 2047. The structure is 234 ft (71.3 m) long and 32 ft wide. If it were closed, the detour would be 6.8 mi (11 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 8 Very Good | No problems noted. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was River RD over Mark West Creek built?
It was built in 1958, making it 67 years old in 2025.
What condition is River RD over Mark West Creek in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in February 2025.
How much traffic does River RD over Mark West Creek carry?
About 8,000 vehicles per day (2018 count), of which roughly 2% are trucks.
How long is River RD over Mark West Creek?
The structure is 234 ft (71.3 m) long with a longest span of 84 ft (25.6 m) and a deck 32 ft wide.
Who owns River RD over Mark West Creek?
It is owned by the County Highway Agency.