Lakes / Iowa / Cerro Gordo County / Mallard Marsh Swamp
Mallard Marsh Swamp, Iowa
31 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Iowa
43.24 degrees N, 93.46 degrees W - Cerro Gordo 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 Mallard Marsh Swamp Stacks Up
- Larger than 11% of the 220 lakes counted in Iowa.
- About 85 miles from Okoboji, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Clear Lake | Cerro Gordo | 8.4 mi | 3,632 acres |
| Rice Lake | Worth | 10 mi | 891 acres |
| Zerbel Slough | Cerro Gordo | 15 mi | 45 acres |
| Eagle Lake | Hancock | 16 mi | 434 acres |
| Crystal Lake | Hancock | 17 mi | 260 acres |
| Silver Lake | Worth | 17 mi | 314 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Mallard Marsh Swamp
How Big Is Mallard Marsh Swamp?
Mallard Marsh Swamp covers 31 acres in Cerro Gordo County, Iowa.
What Is the Largest Lake in Cerro Gordo County?
Clear Lake is the largest lake in Cerro Gordo County, at 3,632 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 130643424). Verified October 30, 2026.