Lakes / Maryland / St. Mary's County / Saint Marys Lake
Saint Marys Lake, Maryland
226 acres
Surface Area
Where It Sits, and How Deep It Goes
Locator - Maryland
38.26 degrees N, 76.54 degrees W - St. Mary's 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 Saint Marys Lake Stacks Up
- Larger than 80% of the 78 lakes counted in Maryland.
- The largest lake in St. Mary's County among those counted.
- About 50 miles from Annapolis, as the crow flies.
Lakes Nearby
| Lake | County | Distance | Surface Area |
|---|---|---|---|
| Green Holly Pond | St. Mary's | 5.1 mi | 31 acres |
| Pond Number Three | St. Mary's | 6.4 mi | 27 acres |
| Chesapeake Ranch Club Lake | Calvert | 10 mi | 72 acres |
| Trinity Lake | Charles | 21 mi | 73 acres |
| Gilbert Pond | Charles | 23 mi | 50 acres |
| Wheatley Lake | Charles | 23 mi | 56 acres |
Straight-line distance between lake centers.
Facts and Figures
Questions About Saint Marys Lake
How Big Is Saint Marys Lake?
Saint Marys Lake covers 226 acres in St. Mary's County, Maryland.
What Is the Largest Lake in St. Mary's County?
Saint Marys Lake is the largest lake in St. Mary's County, at 226 acres.
Largest Lakes in Maryland
| # | Lake | County | Surface Area | Max Depth |
|---|---|---|---|---|
| 1 | Deep Creek Lake | Garrett | 3,679 acres | - |
| 2 | Liberty Lake | Carroll | 2,920 acres | - |
| 3 | Loch Raven Reservoir | Baltimore | 2,200 acres | - |
| 4 | Prettyboy Reservoir | Baltimore | 1,508 acres | - |
| 5 | Triadelphia Reservoir | Montgomery | 794 acres | - |
All 78 Maryland lakes ranked by surface area
Sources: USGS NHD (The National Map NHD MapServer layer 12) named waterbodies FTYPE 390/436; counties via Census point-in-polygon lake data (ID 54018920). Verified October 30, 2026.