Bridge conditions in Miner County, South Dakota
63 inventoried bridges · 19 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Of the 63 Miner County bridges in the federal inventory, 19 carry a poor rating. That 30.2% share is roughly 5x the national average.
- 19 of the 63 bridges in Miner County, South Dakota, are rated in poor condition (30.2%) in the 2025 National Bridge Inventory, as of .
- 19 bridges (30.2%) are rated good and 25 (39.7%) fair.
- The median Miner County bridge was built in 1976.
- The busiest poor-rated bridge is 222 St over Redstone Ck (built 1963), carrying about 320 vehicles a day.
Good 30.2% · Fair 39.7% · Poor 30.2% of 63 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 |
|---|---|---|---|
| 222 St over Redstone Ck | 1963 | 320 | Poor |
| 242 St over West Fork Vermillion Rv | 1972 | 250 | Poor |
| County Rd over Rock Ck | 1930 | 228 | Poor |
| 222 St over West Redstone Ck | 1930 | 148 | Poor |
| 427 Ave over Rock Ck | 1901 | 75 | Poor |
| 428 Ave over Ck | 1940 | 61 | Poor |
| 227 St over Ck | 1925 | 61 | Poor |
| 226 St over E Fork Vermillion Rv | 2000 | 60 | Poor |
| 421 Ave over Redstone Ck | 1930 | 50 | Poor |
| 434 Ave over West Fork Vermillion Rv | 1940 | 40 | Poor |
| Town Street over Redstone Ck | 1955 | 30 | Poor |
| 425 Ave over Rock Ck | 1920 | 30 | Poor |
| 243 St over Rock Ck | 1925 | 25 | Poor |
| 234 St over Rock Ck | 1926 | 25 | Poor |
| 437 Ave over West Fork Vermillion Rv | 1961 | 25 | Poor |
| 427 Ave over Rock Ck | 1930 | 20 | Poor |
| 228 St over Rock Ck | 1930 | 20 | Poor |
| Dirt Trail over Rock Ck | 1910 | 5 | Poor |
| 239TH St. over Rock Ck | 1910 | 5 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| SD034 over West Fork Vermillion Rv | 1987 | 2,168 | Good |
| SD034 over Rock Ck | 1986 | 1,462 | Good |
| SD034 over Ck | 2023 | 970 | Good |
| SD034 over Ck | 2023 | 970 | Good |
| SD025 over West Fork Vermillion Rv | 1953 | 762 | Fair |
| SD025 over Rock Ck | 1976 | 485 | Fair |
| 435 Ave over West Fork Vermillion Rv | 2020 | 336 | Good |
| 222 St over Redstone Ck | 1963 | 320 | Poor |
| 241 St over West Fork Vermillion Rv | 1973 | 250 | Fair |
| 242 St over West Fork Vermillion Rv | 1972 | 250 | Poor |
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.