Lakes / Illinois / Grundy County / Negro Slough
Negro Slough, Illinois
26.69 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Illinois
41.38 degrees N, 88.34 degrees W - Grundy 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 Negro Slough Stacks Up
- Larger than 4% of the 511 lakes counted in Illinois.
- About 50 miles from Chicago, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Heidecke Lake | Grundy | 1.1 mi | 1,913.34 acres |
| Goose Lake | Grundy | 3.8 mi | 40.53 acres |
| Dresden Cooling Lake | Will | 5.7 mi | 1,105.8 acres |
| Milliken Lake | Will | 9.1 mi | 25.95 acres |
| Hawk Lake | Will | 10 mi | 31.41 acres |
| Braidwood Power Plant Cooling Pond | Will | 13 mi | 2,539.39 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Negro Slough
How Big Is Negro Slough?
Negro Slough covers 26.69 acres in Grundy County, Illinois.
What Is the Largest Lake in Grundy County?
Heidecke Lake is the largest lake in Grundy County, at 1,913.34 acres.
Largest Lakes in Illinois
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Carlyle Lake | Clinton | 22,796.77 acres | - |
| 2 | Mine Number 21 Reservoir | Franklin | 17,062.04 acres | - |
| 3 | Upper Peoria Lake | Woodford | 15,460.64 acres | - |
| 4 | Lake Shelbyville | Shelby | 10,235.1 acres | - |
| 5 | Crab Orchard Lake | Williamson | 7,292.57 acres | - |
All 511 Illinois lakes ranked by surface area
Sources: USGS National Hydrography Dataset (The National Map) lake data (ID 90567147). Verified October 30, 2026.