Lakes / Minnesota / Thirty-One
Thirty-One, Minnesota
34 acres
Surface Area
0.94 mi
Shoreline
1,280 ft
Surface Elevation
Where It Sits, and How Deep It Goes
Locator - Minnesota
46.42 degrees N, 93.56 degrees W - Aitkin County. State and county outlines drawn from Census boundary data; the lake marker is placed by its Minnesota DNR coordinates, not by eye. Schematic - not a survey map.
Facts and Figures
Lake ID (DOW)01011400
CountyAitkin
Coordinates46.4245, -93.5552
Deepest Natural Lakes in Minnesota
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Mahnomen, Alstead & Arco Mine | Crow Wing | 272 acres | 525 ft |
| 2 | Sabin | St. Louis | 156 acres | 465 ft |
| 3 | Gilbert Pit | St. Louis | 243 acres | 443 ft |
| 4 | Portsmouth Mine | Crow Wing | 149 acres | 395 ft |
| 5 | St James Pit | St. Louis | 124 acres | 381 ft |
Largest Lakes in Minnesota
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Lake of the Woods | Lake of the Woods | 725,583 acres | 210 ft |
| 2 | Rainy | St. Louis | 210,200 acres | 161 ft |
| 3 | Mille Lacs | Mille Lacs | 128,250 acres | 42 ft |
| 4 | Red (Upper Red) | Beltrami | 119,294 acres | 15 ft |
| 5 | Leech | Cass | 103,444 acres | 150 ft |
Sources: Minnesota DNR lake data (ID 01011400); USGS. Verified October 30, 2026.