Lakes / South Dakota / Shannon County / Alkali Lake
Alkali Lake, Shannon County, South Dakota
311.03 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - South Dakota
43.01 degrees N, 102.09 degrees W - Shannon County. State and county outlines drawn from Census boundary data; the lake marker is placed by its USGS National Hydrography Dataset coordinates, not by eye. Schematic - not a survey map.
How Alkali Lake Stacks Up
- Larger than 74% of the 533 lakes counted in South Dakota.
- About 93 miles from Rapid City, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Two Lance Lake | Shannon | 1.5 mi | 33.36 acres |
| Wakpamani Lake | Shannon | 3.3 mi | 64.99 acres |
| Ross Lake | Bennett | 5.4 mi | 39.04 acres |
| Ecoffey Lake | Bennett | 5.9 mi | 58.81 acres |
| West Lake | Bennett | 6.6 mi | 89.21 acres |
| East Lake | Bennett | 8.5 mi | 44.48 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Alkali Lake
How Big Is Alkali Lake?
Alkali Lake covers 311.03 acres in Shannon County, South Dakota.
What Is the Largest Lake in Shannon County?
Oglala Lake is the largest lake in Shannon County, at 549.32 acres.
Largest Lakes in South Dakota
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Lake Oahe | Dewey | 309,912.57 acres | - |
| 2 | Lake Francis Case | Charles Mix | 82,166.92 acres | - |
| 3 | Lake Sharpe | Hughes | 58,419.67 acres | - |
| 4 | Lewis and Clark Lake | Bon Homme | 25,141.99 acres | - |
| 5 | Lake Thompson | Kingsbury | 13,887.93 acres | - |
All 533 South Dakota lakes ranked by surface area
Sources: USGS National Hydrography Dataset (The National Map) lake data (ID 150497107). Verified October 30, 2026.