St. Mary’s County is a county in Maryland, United States, on the peninsula between the Potomac River and the Chesapeake Bay in the southern part of the state. It had a population of 113,777 at the 2020 census and covers 764 square miles (1,980 km2), of which 357 square miles are land and 407 square miles are water, centred near 38\u00b015\u203208\u2033N 76\u00b033\u203249\u2033W.<\/p>\n
Leonardtown is the county seat, and its postal code is 20650. The county has one incorporated town (Leonardtown), nine census-designated places, and dozens of unincorporated communities and residential developments. It has no civil townships. St. Mary’s County sits in the Eastern time zone.<\/p>\n
St. Mary’s County has a single incorporated municipality, Leonardtown, plus nine census-designated places (CDPs) recognized by the Census Bureau and a large number of unincorporated communities, waterfront subdivisions, and rural crossroads. “CDP” marks a statistically defined place with its own census count; “Unincorp.” marks a named locality with no separate municipal government or reported population.<\/p>\n
| Place<\/th>\n | Type<\/th>\n | Pop.<\/th>\n | ZIP<\/th>\n<\/tr>\n<\/thead>\n |
|---|---|---|---|
| Leonardtown<\/td>\n | Town · seat<\/td>\n | 4,563<\/td>\n | 20650<\/td>\n<\/tr>\n |
| Lexington Park<\/td>\n | CDP<\/td>\n | 13,317<\/td>\n | 20653<\/td>\n<\/tr>\n |
| California<\/td>\n | CDP<\/td>\n | 12,947<\/td>\n | 20619<\/td>\n<\/tr>\n |
| Wildewood<\/td>\n | CDP<\/td>\n | 7,821<\/td>\n | —<\/td>\n<\/tr>\n |
| Golden Beach<\/td>\n | CDP<\/td>\n | 3,651<\/td>\n | —<\/td>\n<\/tr>\n |
| Callaway<\/td>\n | CDP<\/td>\n | 1,779<\/td>\n | —<\/td>\n<\/tr>\n |
| Mechanicsville<\/td>\n | CDP<\/td>\n | 1,673<\/td>\n | 20659<\/td>\n<\/tr>\n |
| Charlotte Hall<\/td>\n | CDP (shared with Charles Co.)<\/td>\n | 1,388<\/td>\n | 20622<\/td>\n<\/tr>\n |
| Piney Point<\/td>\n | CDP<\/td>\n | 980<\/td>\n | 20674<\/td>\n<\/tr>\n |
| Tall Timbers<\/td>\n | CDP<\/td>\n | 451<\/td>\n | 20690<\/td>\n<\/tr>\n |
| St. George Island<\/td>\n | CDP<\/td>\n | 265<\/td>\n | —<\/td>\n<\/tr>\n |
| Abell<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | —<\/td>\n<\/tr>\n |
| Avenue<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20609<\/td>\n<\/tr>\n |
| Barbers Quarter<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | —<\/td>\n<\/tr>\n |
| Bay Forest<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | —<\/td>\n<\/tr>\n |
| Budds Creek<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20629<\/td>\n<\/tr>\n |
| Bushwood<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20618<\/td>\n<\/tr>\n |
| Chaptico<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20621<\/td>\n<\/tr>\n |
| Clements<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20624<\/td>\n<\/tr>\n |
| Coltons Point<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20626<\/td>\n<\/tr>\n |
| Compton<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | —<\/td>\n<\/tr>\n |
| Dameron<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20628<\/td>\n<\/tr>\n |
| Drayden<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20630<\/td>\n<\/tr>\n |
| Great Mills<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20634<\/td>\n<\/tr>\n |
| Helen<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | —<\/td>\n<\/tr>\n |
| Hollywood<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20636<\/td>\n<\/tr>\n |
| Loveville<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20656<\/td>\n<\/tr>\n |
| Maddox<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | —<\/td>\n<\/tr>\n |
| Morganza<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20660<\/td>\n<\/tr>\n |
| Mount Pleasant<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | —<\/td>\n<\/tr>\n |
| Newmarket<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | —<\/td>\n<\/tr>\n |
| Oakville<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | —<\/td>\n<\/tr>\n |
| Park Hall<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20667<\/td>\n<\/tr>\n |
| Ridge<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20680<\/td>\n<\/tr>\n |
| Sandgates<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | —<\/td>\n<\/tr>\n |
| Scotland<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20687<\/td>\n<\/tr>\n |
| St. Inigoes<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20684<\/td>\n<\/tr>\n |
| St. James<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | —<\/td>\n<\/tr>\n |
| Valley Lee<\/td>\n | Unincorp.<\/td>\n | —<\/td>\n | 20692<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n Several entries in older listings for this county were private waterfront subdivisions rather than distinct settlements (Ancient Oaks, Andover Estates, Barefoot Acres, Bates Acres, Beauvue, Beverly Estates, Bluff Woods, Breezy Knolls, Herring Creek Estates, Ponderosa Estates, and similar developments off Route 235 and Route 5) \u2014 these are omitted here because they carry no separate Census Bureau count or postal designation and duplicate the ZIP of a listed community above. Duplicated entries in the old scrape (two “Callaway”, two “Redgate”, two “Wildewood”) are consolidated to a single row each.<\/p>\n ZIP Codes<\/h2>\nPlaces without their own post office, such as Wildewood, Golden Beach, St. George Island, and most subdivisions, are served by the ZIP code of the nearest listed community.<\/p>\n Geography<\/h2>\nSt. Mary’s County occupies the southern tip of the Western Shore, bounded by the Potomac River to the west and south and the Chesapeake Bay to the east, with the Patuxent River forming its northeastern boundary. More than half the county’s total area is water, giving it the second-most land area held back by water of any county in Maryland. The Patuxent Naval Air Station occupies a peninsula near California and Lexington Park, and St. George Island and the Wicomico River shape the county’s southern shoreline.<\/p>\n St. Mary’s County borders Calvert County<\/a> to the northeast across the Patuxent River, Charles County<\/a> to the northwest, and, across the Potomac River to the south and southwest, Northumberland County, Virginia<\/a>, and Westmoreland County, Virginia<\/a>. Across the Chesapeake Bay to the east lies Somerset County, Maryland<\/a>, a water border with no bridge connection.<\/p>\n St. Mary’s County had 113,777 residents at the 2020 census. Lexington Park (13,317) and California (12,947) are the county’s two largest communities, together home to more people than the rest of the county’s named places combined. Median household income in St. Mary’s County runs above the Maryland median of $98,678, driven largely by federal civilian and military pay at Patuxent River Naval Air Station. Population density is roughly 319 people per square mile of land area.<\/p>\n Naval Air Station Patuxent River \u2014 home to Naval Air Systems Command and the U.S. Naval Test Pilot School \u2014 is the county’s dominant employer, drawing a large civilian-contractor workforce to California and Lexington Park. St. Mary’s College of Maryland, a public liberal-arts honors college in Historic St. Mary’s City, and the College of Southern Maryland’s Leonardtown campus anchor the county’s education sector. Tobacco farming shaped St. Mary’s County for three centuries; today agriculture has shifted toward soybeans, wheat, seafood (oysters and blue crab from the Potomac and the Bay), and vineyards. Leonardtown hosts a monthly open-air Wine, Cheese & Chocolate Festival and the county’s annual Oyster Festival.<\/p>\n St. Mary’s County was established in 1637, making it Maryland’s first county and the site of the colony’s original capital, St. Mary’s City, founded in 1634. The county is named for the Virgin Mary. Maryland’s 1649 Toleration Act, passed at the St. Mary’s City statehouse, is regarded as an early legal guarantee of religious freedom in English North America. The colonial capital moved to Annapolis in 1695, after which St. Mary’s City declined; Leonardtown, platted in the 1700s and named for the Leonard family, became the county seat. The 20th-century arrival of the Navy’s flight-test program at Patuxent River, established in 1943, reshaped the county’s economy from tobacco farming toward federal employment.<\/p>\n Maryland Route 235 and Route 5 are the county’s primary north-south corridors, linking Leonardtown, California, and Lexington Park to U.S. Route 301 at the Charles County line.<\/p>\n The nearest commercial airport is Ronald Reagan Washington National Airport, roughly an hour and a half’s drive northwest; St. Mary’s County Regional Airport in California offers general-aviation service.<\/p>\n Where is St. Mary’s County, Maryland?<\/strong> What is the population of St. Mary’s County?<\/strong> How big is St. Mary’s County?<\/strong> What is the county seat of St. Mary’s County?<\/strong> How many towns and communities are in St. Mary’s County?<\/strong> |