407TH Avenue over South Fork Twelve Mile C
Davison County, South Dakota · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 407TH Avenue over South Fork Twelve Mile C in Davison County, South Dakota, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 8 (very good condition) on the 0-9 scale.
- It was built in 2019, making it 6 years old at the 2025 inventory.
- It carries about 64 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 41 of the 123 inventoried bridges in Davison County rated good (33.3%); 22 (17.9%) are rated poor.
- 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 → (43.50827, -98.0639)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 8 | Very good condition |
Bridge details
| Structure | Continuous concrete culvert |
| Length | about 24 ft |
| Location | 2W & 13.4 S Mitchell |
| NBI structure number | 000000018130234 |
| Condition class | Good |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Dakota department of transportation.
Busiest bridges in Davison County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Sanborn St (SD37) over BNSF RR | 2001 | 13,545 | Fair |
| Sanborn St (SD37) over Dry Run Ck | 2001 | 13,545 | Good |
| South Burr Street over Dry Run Ck | 1990 | 11,950 | Good |
| SD037 over I090 | 1966 | 10,351 | Fair |
| SD037 over Dry Run Ck | 1996 | 9,756 | Good |
| SD037 over 4TH Ave BNSF RR | 1997 | 7,642 | Good |
All bridges nearby: Davison County, SD bridge conditions · every bridge in Davison County · South Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.