Montague Grenada over Shasta River
Siskiyou County, California · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Montague Grenada over Shasta River in Siskiyou 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 1972, making it 53 years old at the 2025 inventory.
- It carries about 1,148 vehicles a day (traffic count year 2011).
- Its listed owner is the county highway agency.
- It is one of 170 of the 425 inventoried bridges in Siskiyou County rated good (40.0%); 25 (5.9%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (good), but component ratings moved: superstructure 7 to 8.
- Its most recent inspection on record is dated August 2024, on a 24-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 → (41.70889, -122.53843)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 8 | Very good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Continuous concrete multiple box beam |
| Length | about 152 ft |
| Location | 0.25 Mi N Oberlin Rd |
| NBI structure number | 02C0055 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | August 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in Siskiyou County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Interstate 5 SB over UP RR & Amtrak | 1964 | 20,000 | Fair |
| Interstate 5 NB over UP RR & Amtrak | 1964 | 20,000 | Fair |
| Interstate 5 over Mott Road | 1976 | 20,000 | Good |
| Interstate 5 over Mott Road | 1976 | 20,000 | Fair |
| Interstate 5 over Dunsmuir Ave | 1976 | 19,200 | Good |
| Interstate 5 over Sacramento UP RR Amtrak | 1955 | 18,000 | Good |
All bridges nearby: Siskiyou County, CA bridge conditions · every bridge in Siskiyou County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.