Road M1 over Black Butte River
PoorMendocino County, California · .3 Mi. E. of Eel Riv W.C. · Structure no. 050856000001016
- Built
- 1986
- 39 years old
- Condition
- Poor
- inspected August 2023
- Type
- Box Beam or Girders - Multiple
- Concrete
- Length
- 310 ft
- 1 main span
- Daily traffic
- 50
- Owner
- Federal
- U.S. Forest Service
About this bridge
Road M1 over Black Butte River is a concrete box beam or girders - multiple carrying Road M1 over Black Butte River in Mendocino County, California. It was built in 1986, so it is 39 years old, younger 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 3 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 310 ft (94.5 m) long and 15 ft wide. If it were closed, the detour would be 11.8 mi (19 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 | 7 Good | Some minor problems. |
| Superstructure | 3 Serious | Loss of section, deterioration, spalling or scour have seriously affected primary structural components. |
| 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 Road M1 over Black Butte River built?
It was built in 1986, making it 39 years old in 2025.
What condition is Road M1 over Black Butte River 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 August 2023.
How much traffic does Road M1 over Black Butte River carry?
About 50 vehicles per day (latest count).
How long is Road M1 over Black Butte River?
The structure is 310 ft (94.5 m) long with a longest span of 120 ft (36.6 m) and a deck 15 ft wide.
Who owns Road M1 over Black Butte River?
It is owned by the U.S. Forest Service.