C 843 over Middle Fk. Yuba River
Sierra County, California · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- C 843 over Middle Fk. Yuba River in Sierra County, California, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1965, making it 60 years old at the 2025 inventory.
- It carries about 50 vehicles a day.
- It is one of 33 of the 66 inventoried bridges in Sierra County rated fair (50.0%); 4 (6.1%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated August 2023, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (39.50891, -120.55902)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Continuous concrete girder and floorbeam |
| Length | about 102 ft |
| Location | S18 T19N R13E |
| NBI structure number | 051756000001027 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | August 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in Sierra County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| U.S. Highway 395 over Long Valley Rd | 1976 | 4,600 | Good |
| U.S. Highway 395 over Long Valley Rd | 1976 | 2,300 | Good |
| State Route 89 over Little Truckee River | 1982 | 2,000 | Fair |
| State Route 49 over Smithneck Creek | 1965 | 1,900 | Good |
| State Route 89 over Turner Canyon | 1975 | 1,400 | Good |
| State Route 49 over Downie River | 1938 | 1,200 | Good |
All bridges nearby: Sierra County, CA bridge conditions · every bridge in Sierra County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.