Bridge conditions in Grant County, South Dakota
205 inventoried bridges · 38 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Grant County has 38 bridges rated poor out of 205 inventoried, a 18.5% share that puts it well above the national rate of about 7%.
- 38 of the 205 bridges in Grant County, South Dakota, are rated in poor condition (18.5%) in the 2025 National Bridge Inventory, as of .
- 100 bridges (48.8%) are rated good and 67 (32.7%) fair.
- The median Grant County bridge was built in 1997.
- The busiest poor-rated bridge is 2ND Avenue over BNSF Railroad (built 1914), carrying about 2,560 vehicles a day.
Good 48.8% · Fair 32.7% · Poor 18.5% of 205 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 |
|---|---|---|---|
| 2ND Avenue over BNSF Railroad | 1914 | 2,560 | Poor |
| W. Milbank St-milb over South Fork Whetstone Rv | 1984 | 696 | Poor |
| 147 Street over Ck | 1926 | 100 | Poor |
| 147 Street over Ck | 1926 | 100 | Poor |
| 163 Street over South Fork Yellow Bank R | 1930 | 98 | Poor |
| 480 Avenue over Ck | 1969 | 96 | Poor |
| 475 Avenue over Ck | 1965 | 75 | Poor |
| 482 Avenue over Whetstone Rv | 1978 | 57 | Poor |
| 466 Avenue over Ck | 1930 | 54 | Poor |
| 148 Street over Big Sioux Rv | 1930 | 52 | Poor |
| 152 Street over Indian Rv | 1932 | 52 | Poor |
| 142 Street over Ck | 1958 | 52 | Poor |
| 144 Street over North Fork Whetstone Rv | 1965 | 52 | Poor |
| 485 Avenue over Ck | 1955 | 52 | Poor |
| 161 Street over S Fork Yellow Bank River | 1940 | 52 | Poor |
| 161 Street over S Fork Yellow Bank River | 1940 | 52 | Poor |
| 151 Street over Big Sioux Rv | 1958 | 45 | Poor |
| 156 Street over Ck | 1935 | 40 | Poor |
| 481 Avenue over Ck | 1930 | 40 | Poor |
| 456 Avenue over Indian River | 1960 | 35 | Poor |
| 150 Street over Ck | 1925 | 35 | Poor |
| 485 Avenue over North Fork Yellow Bank R | 1930 | 35 | Poor |
| 485 Avenue over Ck | 1948 | 35 | Poor |
| 485 Avenue over Ck | 1950 | 35 | Poor |
| 487 Avenue over North Fork Yellow Bank R | 1958 | 35 | Poor |
| 476 Avenue over Ck | 1930 | 27 | Poor |
| 165 Street over South Fork Yellow Bank R | 1940 | 26 | Poor |
| 469 Avenue over Ck | 1930 | 25 | Poor |
| 471 Avenue over Ck | 1926 | 25 | Poor |
| 473 Avenue over South Fork Whetstone Rv | 1942 | 25 | Poor |
| 473 Avenue over Ck | 1936 | 25 | Poor |
| 474 Ave over Ck | 1901 | 25 | Poor |
| 483 Avenue over Whetstone Rv | 1962 | 25 | Poor |
| 454 Avenue over Indian River | 1936 | 20 | Poor |
| Center Road over Ck | 1927 | 20 | Poor |
| 477 Avenue over Ck | 1965 | 18 | Poor |
| 474 Avenue over Ck | 1926 | 15 | Poor |
| 160 Street over Ck | 1991 | 10 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Irr I029 over Indian Rv | 1976 | 6,600 | Fair |
| US012 over Whetstone Rv Div Channel | 1955 | 3,765 | Fair |
| Irr I029 S over 146 St | 1977 | 3,650 | Fair |
| Irr I029 N over 146 St | 1977 | 3,650 | Good |
| Irr I029 S over 149 St (fas 6266) | 1976 | 3,650 | Fair |
| Irr I029 N over 149 St (fas 6266) | 1976 | 3,650 | Fair |
| I029 S over 152 St | 1977 | 3,605 | Fair |
| I029 N over 152 St | 1976 | 3,605 | Fair |
| US012 over Whetstone Rv | 2003 | 3,334 | Good |
| 2ND Avenue over BNSF Railroad | 1914 | 2,560 | 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.