Bridge conditions in Aurora County, South Dakota
61 inventoried bridges · 7 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
About one in 9 bridges in Aurora County is rated in poor condition: 7 of 61 on the federal inventory, one of the higher shares in South Dakota.
- 7 of the 61 bridges in Aurora County, South Dakota, are rated in poor condition (11.5%) in the 2025 National Bridge Inventory, as of .
- 25 bridges (41.0%) are rated good and 29 (47.5%) fair.
- The median Aurora County bridge was built in 1965.
- The busiest poor-rated bridge is 242 St over Ck (built 1917), carrying about 101 vehicles a day.
Good 41.0% · Fair 47.5% · Poor 11.5% of 61 bridges
Bridges rated poor
Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| 242 St over Ck | 1917 | 101 | Poor |
| 265 St over Platte Ck | 1967 | 66 | Poor |
| 246 St over Firesteel Ck | 1930 | 65 | Poor |
| 378 Ave over West Firesteel Ck | 1936 | 62 | Poor |
| 383 Ave over West Firesteel Ck | 1973 | 33 | Poor |
| 244 St over Firesteel Ck | 1940 | 33 | Poor |
| 391 Ave over West Firesteel Ck | 1925 | 33 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I090 over Ck | 1965 | 9,890 | Fair |
| I090 W over Platte Ck | 1964 | 4,425 | Fair |
| I090 E over Platte Ck | 1964 | 4,425 | Fair |
| US281 over I090 | 1965 | 1,694 | Fair |
| US281 over Ck | 2007 | 1,434 | Good |
| US281 over West Br Firesteel Ck | 1959 | 1,284 | Fair |
| US281 over Ck | 1960 | 1,284 | Fair |
| US281 over Firesteel Ck | 1959 | 1,104 | Good |
| US281 over Branch of Firesteel Ck | 1959 | 1,104 | Good |
| SD258 over Snow Ck | 1965 | 798 | Good |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of South Dakota: South Dakota bridge conditions by county · every download on the data page.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.