South Dakota Highway 109
Route of SD 109 (in red) | ||||
| Route information | ||||
| Maintained by SDDOT | ||||
| Length | 12.167 mi (19.581 km) | |||
| Existed | 1975–present | |||
| History | SD 15Y: 1962–1975 | |||
| Major junctions | ||||
| South end | US 12 in Big Stone City | |||
| North end | SD 15 in Geneseo Township | |||
| Location | ||||
| Country | United States | |||
| State | South Dakota | |||
| Counties | Grant, Roberts | |||
| Highway system | ||||
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South Dakota Highway 109 (SD 109) is a 12.167-mile (19.581 km) state highway in Grant and Roberts counties in South Dakota, United States, runs along the south side of Big Stone Lake and the Minnesota border from U.S. Route 12 in Big Stone City to South Dakota Highway 15.