US 20 over Rock Creek
Blaine County, Idaho · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 20 over Rock Creek in Blaine County, Idaho, 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 2019, making it 6 years old at the 2025 inventory.
- It carries about 2,200 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 65 of the 96 inventoried bridges in Blaine County rated fair (67.7%); 4 (4.2%) are rated poor.
- 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 → (43.3345, -114.38136)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 6 | Satisfactory condition |
| Superstructure | 8 | Very good condition |
| Substructure | 8 | Very good condition |
Bridge details
| Structure | Concrete stringer or multi-beam girder |
| Length | about 159 ft |
| Location | 20.7 E. Fairfield |
| NBI structure number | 000000000034435 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Idaho department of transportation.
Busiest bridges in Blaine County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| SH 75 over Big Wood River | 2002 | 14,500 | Good |
| SH 75 over Big Wood River | 2017 | 14,500 | Fair |
| SH 75 over Bellevue Canal | 1931 | 7,000 | Fair |
| STC2815;WARM Sprng over Big Wood River | 1972 | 6,300 | Fair |
| Dollar Road over Trail Creek | 1988 | 5,000 | Good |
| SH 75 over Richfield Canal | 1955 | 4,500 | Fair |
All bridges nearby: Blaine County, ID bridge conditions · every bridge in Blaine County · Idaho bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.