Lakes / South Dakota / Tripp County / Hamill Dam Reservoir
Hamill Dam Reservoir, South Dakota
34.1 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - South Dakota
43.60 degrees N, 99.68 degrees W - Tripp 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 Hamill Dam Reservoir Stacks Up
- Larger than 7% of the 533 lakes counted in South Dakota.
- About 63 miles from Pierre, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Heap Lake | Lyman | 17 mi | 69.23 acres |
| Lake Burch | Gregory | 17 mi | 110.46 acres |
| Reliance Lake | Lyman | 20 mi | 41.51 acres |
| Byre Lake | Lyman | 24 mi | 84.51 acres |
| Brakke Dam | Lyman | 24 mi | 86.49 acres |
| Red Lake | Brule | 24 mi | 151.48 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Hamill Dam Reservoir
How Big Is Hamill Dam Reservoir?
Hamill Dam Reservoir covers 34.1 acres in Tripp County, South Dakota.
What Is the Largest Lake in Tripp County?
Dog Ear Lake is the largest lake in Tripp County, at 241.02 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 146672789). Verified October 30, 2026.