Big Stone Lake
| Big Stone Lake | |
|---|---|
| Íŋyaŋ Tháŋka Bdé | |
Big Stone Lake from Ortonville's Lakeside Park, September 2013 | |
| Location | Big Stone County, Minnesota / Roberts County and Grant County, South Dakota |
| Coordinates | 45°24′28″N 96°37′04″W / 45.40778°N 96.61778°W |
| Type | reservoir |
| Primary inflows | Little Minnesota River |
| Primary outflows | Minnesota River |
| Basin countries | United States |
| Max. length | 26 mi (42 km) |
| Surface area | 12,610 acres (5,100 ha) |
| Max. depth | 16 ft (4.9 m) |
| Surface elevation | 968 ft (295 m) |
| Settlements | Ortonville MN, Big Stone City SD, Browns Valley MN |
Big Stone Lake (Dakota: Íŋyaŋ Tháŋka Bdé) is a long, narrow freshwater lake and reservoir on the border between western Minnesota and northeastern South Dakota in the United States.