South Fork Road over Kerlin Creek
Trinity County, California · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- South Fork Road over Kerlin Creek in Trinity County, California, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1960, making it 65 years old at the 2025 inventory.
- It carries about 160 vehicles a day (traffic count year 2010).
- Its listed owner is the county highway agency.
- It is one of 75 of the 194 inventoried bridges in Trinity County rated fair (38.7%); 7 (3.6%) 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 May 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 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 → (40.63466, -123.48378)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 29 ft |
| Location | 3.8 Mi N Hyampom Rd |
| NBI structure number | 05C0122 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | May 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in Trinity County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| State Route 299 over East Weaver Creek | 1962 | 7,125 | Fair |
| State Route 299 over Weaver Creek | 1953 | 5,375 | Fair |
| State Route 299 over Little Browns Creek | 1999 | 5,375 | Good |
| State Route 299 over Trinity River | 1980 | 4,450 | Fair |
| State Route 299 over Indian Creek | 1974 | 4,050 | Fair |
| State Route 299 over Gray Creek | 1966 | 3,800 | Fair |
All bridges nearby: Trinity County, CA bridge conditions · every bridge in Trinity County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.