Walnut Grove Road over Mokelumne River
San Joaquin County, California · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Walnut Grove Road over Mokelumne River in San Joaquin County, California, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1955, making it 70 years old at the 2025 inventory.
- It carries about 2,084 vehicles a day (traffic count year 2015).
- Its listed owner is the county highway agency.
- It is one of 63 of the 655 inventoried bridges in San Joaquin County rated poor (9.6%); 63 (9.6%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (poor), but component ratings moved: superstructure 5 to 7.
- Its most recent inspection on record is dated January 2024, on a 24-month routine inspection cycle.
- It has fracture-critical members (NBI item 92A): steel tension members without a redundant load path, which get their own scheduled inspections.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (38.22365, -121.50735)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 4 | 4 | Poor condition |
| Superstructure | 5 | 7 | Good condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Steel movable swing |
| Length | about 237 ft |
| Location | at Sj & Sac County Line |
| NBI structure number | 29C0131 |
| Condition class | Poor |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | January 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | U: unknown foundation, not evaluated for scour |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in San Joaquin County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Interstate 5 SB over Paradise Cut | 1947 | 143,000 | Fair |
| Interstate 5 NB over Brookside Calaveras Riv | 1968 | 124,000 | Poor |
| Interstate 5 NB over Country Club Blvd | 1970 | 124,000 | Fair |
| Interstate 5 NB over Michigan Ave | 1970 | 124,000 | Fair |
| Interstate 5 NB over Alpine Ave | 1970 | 124,000 | Fair |
| Interstate 5 NB over Telegraph Ave | 1970 | 124,000 | Fair |
All bridges nearby: San Joaquin County, CA bridge conditions · every bridge in San Joaquin County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.