Lakes / Illinois / Menard County / Lake Petersburg
Lake Petersburg, Illinois
177.42 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Illinois
39.99 degrees N, 89.86 degrees W - Menard 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 Petersburg Stacks Up
- Larger than 74% of the 511 lakes counted in Illinois.
- About 18 miles from Springfield, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Finger Lake | Cass | 15 mi | 27.43 acres |
| Wolf Lake | Mason | 17 mi | 35.09 acres |
| Sudduth Lake | Sangamon | 19 mi | 36.82 acres |
| Clear Lake | Sangamon | 21 mi | 136.4 acres |
| Moscow Lake | Mason | 21 mi | 249.33 acres |
| Patterson Bay | Mason | 21 mi | 50.66 acres |
Straight-line distance between lake centers.
Facts and Figures
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 133215326). Verified October 30, 2026.