Lakes / Illinois / Lake County / Grass Lake
Grass Lake, Illinois
1,582.22 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Illinois
42.44 degrees N, 88.16 degrees W - Lake 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 Grass Lake Stacks Up
- Larger than 94% of the 511 lakes counted in Illinois.
- About 48 miles from Chicago, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Turner Lake | Lake | 1.6 mi | 42.26 acres |
| Spring Lake | Lake | 1.8 mi | 32.62 acres |
| Bluff Lake | Lake | 1.8 mi | 101.07 acres |
| Petite Lake | Lake | 1.8 mi | 195.71 acres |
| Dunns Lake | Lake | 1.9 mi | 66.97 acres |
| Nippersink Lake | Lake | 2.2 mi | 2,492.93 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Grass Lake
How Big Is Grass Lake?
Grass Lake covers 1,582.22 acres in Lake County, Illinois.
What Is the Largest Lake in Lake County?
Nippersink Lake is the largest lake in Lake County, at 2,492.93 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 121650552). Verified October 30, 2026.