Lakes / South Dakota / Bennett County / Ecoffey Lake
Ecoffey Lake, South Dakota
58.81 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - South Dakota
43.03 degrees N, 101.98 degrees W - Bennett 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 Ecoffey Lake Stacks Up
- Larger than 21% of the 533 lakes counted in South Dakota.
- About 96 miles from Rapid City, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| West Lake | Bennett | 1.4 mi | 89.21 acres |
| Ross Lake | Bennett | 2.0 mi | 39.04 acres |
| East Lake | Bennett | 3.2 mi | 44.48 acres |
| Robinson Lake | Bennett | 4.7 mi | 49.17 acres |
| Alkali Lake | Shannon | 5.9 mi | 311.03 acres |
| Two Lance Lake | Shannon | 6.9 mi | 33.36 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Ecoffey Lake
How Big Is Ecoffey Lake?
Ecoffey Lake covers 58.81 acres in Bennett County, South Dakota.
What Is the Largest Lake in Bennett County?
Little White River Pool Reservoir is the largest lake in Bennett County, at 569.08 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 150497097). Verified October 30, 2026.