Lakes / South Dakota / Dewey County
Lakes in Dewey County, South Dakota
11 lakes counted in Dewey County - the largest is Lake Oahe at 309,912.57 acres.
11
Lakes Counted
309,912.57 acres
Largest - Lake Oahe
Dewey County, highlighted, with its largest counted lakes dotted. Outlines from Census boundary data.
All Counted Lakes
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Lake Oahe | Dewey | 309,912.57 acres | - |
| 2 | Timber Lake | Dewey | 424.08 acres | - |
| 3 | Isabel Lake | Dewey | 107.99 acres | - |
| 4 | Whitehorse Lake | Dewey | 87.23 acres | - |
| 5 | Horseshoe Lake | Dewey | 81.79 acres | - |
| 6 | Livermant Lake | Dewey | 64.49 acres | - |
| 7 | Peach Lake | Dewey | 54.36 acres | - |
| 8 | Goose Creek Dam | Dewey | 44.23 acres | - |
| 9 | Little Moreau Lake | Dewey | 33.85 acres | - |
| 10 | Lantry Lake | Dewey | 27.92 acres | - |
| 11 | Eagle Butte Lake | Dewey | 25.56 acres | - |
Sources: USGS National Hydrography Dataset lake data; USGS. Verified October 30, 2026.