121ST Ave over Green River
Billings County, North Dakota · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 121ST Ave over Green River in Billings County, North Dakota, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1946 and reconstructed in 1975, making it 79 years old at the 2025 inventory.
- It carries about 26 vehicles a day (traffic count year 2018).
- Its listed owner is the county highway agency.
- It is one of 21 of the 60 inventoried bridges in Billings County rated fair (35.0%); 2 (3.3%) 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 → (47.02693, -103.05401)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 7 | Good condition |
| Superstructure | 7 | Good condition |
| Substructure | 6 | Satisfactory condition |
Bridge details
| Structure | Prestressed concrete channel beam |
| Length | about 49 ft |
| Location | 8 East 12 South Fairfield |
| NBI structure number | 000000004129210 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the North Dakota department of transportation.
Busiest bridges in Billings County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Interstate 94 over Sheep Creek | 1964 | 2,600 | Fair |
| Interstate 94 over West River Rd. Int. | 1968 | 1,525 | Fair |
| Interstate 94 over West River Rd. Int. | 1968 | 1,525 | Fair |
| Interstate 94 over Little Missouri R. | 1964 | 1,300 | Fair |
| Interstate 94 over Little Missouri R. | 1964 | 1,300 | Fair |
| Interstate 94 over Sheep Creek | 1964 | 1,300 | Fair |
All bridges nearby: Billings County, ND bridge conditions · every bridge in Billings County · North Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.