Lakes / Iowa / Union County / Three Mile Lake
Three Mile Lake, Iowa
836 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Iowa
41.09 degrees N, 94.23 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 Three Mile Lake Stacks Up
- Larger than 92% of the 220 lakes counted in Iowa.
- The largest lake in Union County among those counted.
- About 46 miles from Des Moines, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Twelve Mile Lake | Union | 2.4 mi | 644 acres |
| Green Valley Lake | Union | 8.3 mi | 330 acres |
| Summit Lake | Union | 8.9 mi | 105 acres |
| Sun Valley Lake | Ringgold | 18 mi | 398 acres |
| Greenfield Lake | Adair | 19 mi | 27 acres |
| Nodaway Lake | Adair | 19 mi | 26 acres |
Straight-line distance between lake centers.
Facts and Figures
Waterbody ID{3D0D96EC-4842-4951-B7CD-286E78D05610}
CountyUnion
Lake TypeReservoir
Coordinates41.0905, -94.2302
Questions About Three Mile Lake
How Big Is Three Mile Lake?
Three Mile Lake covers 836 acres in Union County, Iowa.
What Is the Largest Lake in Union County?
Three Mile Lake is the largest lake in Union County, at 836 acres.
Largest Lakes in Iowa
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Rathbun Lake | Appanoose | 13,869 acres | - |
| 2 | Lake Red Rock | Marion | 8,619 acres | - |
| 3 | Spirit Lake | Dickinson | 5,463 acres | - |
| 4 | Saylorville Lake | Polk | 5,428 acres | - |
| 5 | Clear Lake | Cerro Gordo | 3,632 acres | - |
All 220 Iowa lakes ranked by surface area
Sources: USGS NHD (The National Map NHD MapServer layer 12) named waterbodies FTYPE 390/436; counties via Census point-in-polygon lake data (ID {3D0D96EC-4842-4951-B7CD-286E78D05610}). Verified October 30, 2026.