Lakes / Illinois / Montgomery County / Lake Hillsboro
Lake Hillsboro, Illinois
105.51 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Illinois
39.17 degrees N, 89.47 degrees W - Montgomery 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 Lake Hillsboro Stacks Up
- Larger than 62% of the 511 lakes counted in Illinois.
- About 43 miles from Springfield, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Lake Glenn Shoals | Montgomery | 2.7 mi | 1,097.06 acres |
| Lake Lou Yaeger | Montgomery | 7.8 mi | 1,369.33 acres |
| Coffeen Lake | Montgomery | 9.4 mi | 881.18 acres |
| Walton Lake | Montgomery | 10 mi | 29.16 acres |
| Fivemile Lake | Montgomery | 11 mi | 71.41 acres |
| Old Mount Olive Reservoir | Macoupin | 16 mi | 35.34 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Lake Hillsboro
How Big Is Lake Hillsboro?
Lake Hillsboro covers 105.51 acres in Montgomery County, Illinois.
What Is the Largest Lake in Montgomery County?
Lake Lou Yaeger is the largest lake in Montgomery County, at 1,369.33 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 149994227). Verified October 30, 2026.