Irr Co Rd 87 over Roberts Slough
Modoc County, California · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Irr Co Rd 87 over Roberts Slough in Modoc County, California, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1955, making it 70 years old at the 2025 inventory.
- It carries about 255 vehicles a day (traffic count year 2012).
- Its listed owner is the county highway agency.
- It is one of 43 of the 87 inventoried bridges in Modoc County rated good (49.4%); 1 (1.1%) 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 April 2023, on a 48-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (41.21535, -121.12863)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Concrete slab |
| Length | about 22 ft |
| Location | 0.9 Mi NE Lkot Hkamore Rd |
| NBI structure number | 03C0004 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | April 2023 |
| Inspection interval (item 91) | 48 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 Modoc County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| U.S. Highway 395 over North Fork Pit River | 1982 | 4,000 | Fair |
| U.S. Highway 395 over Parker Creek | 1954 | 4,000 | Fair |
| State Route 299 over Rattlesnake Creek | 1980 | 3,000 | Good |
| State Route 299 over Rock Creek | 1937 | 2,800 | Good |
| U.S. Highway 395 over South Fork Pit River | 1971 | 2,400 | Fair |
| U.S. Highway 395 over South Fork Pit River | 1971 | 2,400 | Good |
All bridges nearby: Modoc County, CA bridge conditions · every bridge in Modoc County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.