Lakes / South Dakota / Union County / McCook Lake
McCook Lake, South Dakota
190.77 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - South Dakota
42.54 degrees N, 96.51 degrees W - Union 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 McCook Lake Stacks Up
- Larger than 63% of the 533 lakes counted in South Dakota.
- The largest lake in Union County among those counted.
- About 70 miles from Sioux Falls, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Lake Nixon | Union | 19 mi | 43.74 acres |
| Burbank Lake | Union | 19 mi | 34.59 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About McCook Lake
How Big Is McCook Lake?
McCook Lake covers 190.77 acres in Union County, South Dakota.
What Is the Largest Lake in Union County?
McCook Lake is the largest lake in Union County, at 190.77 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 128453478). Verified October 30, 2026.