Bridge conditions in Butte County, South Dakota
142 inventoried bridges · 20 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Butte County has 20 bridges rated poor out of 142 inventoried, a 14.1% share that puts it well above the national rate of about 7%.
- 20 of the 142 bridges in Butte County, South Dakota, are rated in poor condition (14.1%) in the 2025 National Bridge Inventory, as of .
- 46 bridges (32.4%) are rated good and 76 (53.5%) fair.
- The median Butte County bridge was built in 1978.
- The busiest poor-rated bridge is Arpan Rd over South Canal (built 1975), carrying about 269 vehicles a day.
Good 32.4% · Fair 53.5% · Poor 14.1% of 142 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 |
|---|---|---|---|
| Arpan Rd over South Canal | 1975 | 269 | Poor |
| Old Hwy 212 over Station Elm Ck | 1945 | 48 | Poor |
| Gaver Road over Redwater Rv | 1920 | 47 | Poor |
| Olson Cutoff Road over Belle Fourche Rv | 1995 | 47 | Poor |
| Brooker Rd over Indian Ck | 1950 | 47 | Poor |
| Brooker Rd over Hilder Brand Ck | 1985 | 47 | Poor |
| Winkler Rd over Horse Ck | 1958 | 47 | Poor |
| Ypparilla Rd over Ck | 1960 | 47 | Poor |
| Eicher Rd over Horse Ck | 1950 | 47 | Poor |
| Old Hwy 212 over Dry Ck | 1970 | 47 | Poor |
| Youngberg Road over Horse Ck | 1978 | 47 | Poor |
| Old Hwy 212 over Ck | 1950 | 47 | Poor |
| Dillinger Rd over Horse Ck | 1937 | 46 | Poor |
| Youngberg Rd over Dry Ck | 1945 | 32 | Poor |
| Old Hwy 85 over Four Mile Ck | 1945 | 25 | Poor |
| Old Hwy 85 over Battle Ck | 1945 | 25 | Poor |
| Mail Rd over Indian Ck | 1940 | 22 | Poor |
| Old Hwy 79 over South Fork Moreau Rv | 1930 | 22 | Poor |
| Kling Rd over Hay Ck | 1930 | 12 | Poor |
| Vale Cutoff Rd over Belle Fourche Rv | 1974 | 10 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US085 over Hay Ck | 1963 | 15,432 | Fair |
| US085 over Belle Fourche Rv | 1958 | 10,476 | Fair |
| SD034 over Willow Ck | 1939 | 3,961 | Fair |
| SD034 over Redwater Rv | 1992 | 3,547 | Fair |
| SD034 over Redwater Canal | 1964 | 3,547 | Good |
| SD034 over False Bottom Ck | 1992 | 3,547 | Fair |
| US212 over Belle Fourche Rv | 1992 | 2,874 | Fair |
| US212 over Horse Ck | 2005 | 2,454 | Good |
| SD079 over Cottonwood Ck | 1954 | 1,935 | Fair |
| US212 over Belle Fourche Rv | 2002 | 1,790 | Fair |
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.