Lakes / Illinois / Williamson County / Herrin Reservoir
Herrin Reservoir, Illinois
50.41 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Illinois
37.76 degrees N, 89.03 degrees W - Williamson 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 Herrin Reservoir Stacks Up
- Larger than 36% of the 511 lakes counted in Illinois.
- About 10 miles from Carbondale, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Pond 17 | Williamson | 3.2 mi | 39.04 acres |
| Crab Orchard Lake | Williamson | 4.3 mi | 7,292.57 acres |
| Madison Lake | Williamson | 5.4 mi | 26.19 acres |
| Marion Reservoir | Williamson | 7.2 mi | 245.13 acres |
| Sweet Lake | Williamson | 8.2 mi | 36.57 acres |
| Teal Lake | Williamson | 8.4 mi | 29.65 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Herrin Reservoir
How Big Is Herrin Reservoir?
Herrin Reservoir covers 50.41 acres in Williamson County, Illinois.
What Is the Largest Lake in Williamson County?
Crab Orchard Lake is the largest lake in Williamson County, at 7,292.57 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 48806872). Verified October 30, 2026.