Bridge conditions in Oglala Lakota County, South Dakota
35 inventoried bridges · 2 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Oglala Lakota County tracks close to typical: 2 of its 35 inventoried bridges (5.7%) are rated poor, against a national rate of about 7%.
- 2 of the 35 bridges in Oglala Lakota County, South Dakota, are rated in poor condition (5.7%) in the 2025 National Bridge Inventory, as of .
- 20 bridges (57.1%) are rated good and 13 (37.1%) fair.
- The median Oglala Lakota County bridge was built in 2007.
- The busiest poor-rated bridge is Moccasin Park Rd over White Clay Creek (built 1975), carrying about 50 vehicles a day.
Good 57.1% · Fair 37.1% · Poor 5.7% of 35 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 |
|---|---|---|---|
| Moccasin Park Rd over White Clay Creek | 1975 | 50 | Poor |
| Smithwick Road over White River | 1935 | 10 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Irr Bia Rte 36 over White Clay Creek | 2001 | 7,551 | Good |
| Irr US018 over Wolf Ck | 2006 | 5,154 | Fair |
| Irr US018 over Ck | 2016 | 3,597 | Good |
| Irr US018 over Ck | 2011 | 3,274 | Good |
| Irr US018 over Cheyenne Ck | 2020 | 3,274 | Good |
| Irr Bia Rte 27 over White River | 1985 | 2,368 | Fair |
| Irr US018 over White Clay Ck | 2011 | 2,131 | Fair |
| Irr US018 over Trib. to White Clay Ck | 2011 | 2,131 | Good |
| Irr US018 over Trib. to White Clay Ck | 2011 | 2,131 | Good |
| Irr US018 over Ck | 2011 | 2,131 | 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.