St. Mary’s County, Maryland
At the southern tip of Maryland, St. Mary’s County is where the Potomac River meets the Chesapeake Bay. Known as the birthplace of Maryland, the county is home to St. Mary’s City, the site of the state’s first colonial settlement.
Visitors can explore the region’s history at Historic St. Mary’s City, a living-history museum that brings Maryland’s colonial past to life. The county is also home to Patuxent River Naval Air Station, an important part of the local community.
With miles of shoreline, fishing, boating, and crabbing are popular activities throughout St. Mary’s County. The area also offers a slower pace of life, with farms, vineyards, and local markets adding to the county’s rural character.
| Category | Details |
|---|---|
| County Name | St. Mary’s County |
| County Seat | Leonardtown |
| Etymology | Named in honor of St. Mary and the religious significance of its name. |
| Cities, Towns, and Communities | Leonardtown, California, Lexington Park, Great Mills, St. Inigoes, and others |
| Interstates and Highways | U.S. Route 235, Maryland Route 4, Maryland Route 5, Maryland Route 235 |
| FIPS Code | 24-037 |
| Total Area (Land and Water) | 370.0 square miles (land: 357.1 sq mi, water: 12.9 sq mi) |
| Adjacent Counties (and Direction) | Calvert County (Northeast), Charles County (Northwest), Somerset County (Southeast), Northumberland County, Virginia (South), Westmoreland County, Virginia (Southwest), Dorchester County (East) |
| Time Zone | Eastern Time Zone (EST) |
| State | Maryland |
| Coordinates | 38.22°N, 76.77°W |
| Major Landmarks | Historic St. Mary’s City, Point Lookout State Park, Piney Point Lighthouse, Patuxent River Naval Air Station |
| Population | 115,000 |
TRANSPORTATION MAP
St. Mary’s County Road Map
Explore roads, waterways, and landmarks in greater detail with our road map and zoom tool below. Route 235 and Route 5 serve as the main north-south arteries across the peninsula, connecting communities throughout St. Mary’s County.
SATELLITE IMAGERY
St. Mary’s County Satellite Map
Our St. Mary’s County satellite map shows a landscape shaped by peninsulas, inlets, and waterways. Dense forests alternate with agricultural fields and developed waterfront areas, creating a varied coastal landscape across the county.
OUTLINE MAP
St. Mary’s County Blank Map
St. Mary’s County is surrounded by water on three sides, with only a narrow land connection to Charles County along its northern boundary.
Maryland County Maps
Maryland County Map
With 23 counties and Baltimore City, Maryland offers a diverse mix of cities, small towns, rural communities, and scenic outdoor landscapes. From the Chesapeake Bay and coastal areas to historic towns and mountain regions, every part of the state has its own character. Explore our detailed Maryland county maps to learn more about the state’s counties, cities, roads, boundaries, and geographic features.