Lakes / Illinois / Lake County / Forest Lake
Forest Lake, Illinois
39.54 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Illinois
42.21 degrees N, 88.05 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 Forest Lake Stacks Up
- Larger than 26% of the 511 lakes counted in Illinois.
- About 32 miles from Chicago, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Sylvan Lake | Lake | 2.1 mi | 31.88 acres |
| Lake Zurich | Lake | 2.8 mi | 233.02 acres |
| Countryside Lake | Lake | 2.8 mi | 140.85 acres |
| Diamond Lake | Lake | 3.5 mi | 152.46 acres |
| Lake Sheree | Lake | 3.6 mi | 30.15 acres |
| Davis Lake | Lake | 3.8 mi | 33.11 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Forest Lake
How Big Is Forest Lake?
Forest Lake covers 39.54 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 109984954). Verified October 30, 2026.