Structure 50854000001001 · Lake County, CA
Carries Road M1 over Eel River, 13 Miles NE Potter Valley.
303 ft end to end: about 4 semi-trucks nose to tail. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a box-beam bridge.
| State | California |
| County | Lake |
| Location | 13 Miles NE Potter Valley |
| Carries | Road M1 |
| Crosses | Eel River |
| Coordinates | 39.74274, -123.04480 |
| Material | Concrete |
| Design | Box Beam - Multiple |
| Total Length | 302.8 ft (92.3 m) |
| Max Span | 120.1 ft (36.6 m) |
| Deck Width | 31.8 ft (9.7 m) |
| Deck Area | 895.3 sq m |
| Main Spans | 1 |
| Year Built | 1971 |
| Avg Daily Traffic | 350 (1992) |
| Truck Traffic | 3% |
| Lanes On Bridge | 2 |
| Last Inspection | August 2023 |
| Inspection Frequency | Every 12 months |
| Owner | U.S. Forest Service |
| Historical Significance | Historical significance is not determined |
| Scour Critical | 4 — Foundations need monitoring |
| Structure Number | 050854000001001 |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.