Maryland Geography, Climate & Nature

Geography

Maryland covers 12,407 square miles, the ninth-smallest U.S. state by land area, comparable in size to Belgium. It borders Pennsylvania to the north, Delaware to the northeast, the Atlantic Ocean to the east, and West Virginia and Virginia to the west and south, with the U.S. capital carved out of land Maryland ceded to the federal government in 1790. The Chesapeake Bay, the largest estuary in the United States, nearly bisects the state; the counties east of it are collectively the Eastern Shore, and the counties west of it the Western Shore.

The bay itself runs about 200 miles from the Susquehanna River's headwaters to the Atlantic, ranging from 2.8 miles wide at its narrowest to 30 miles at its widest, with an average depth of 21 feet and a maximum of 174 feet; more than 150 rivers and streams feed a drainage basin covering parts of six states. Western Maryland rises into the Appalachian Mountains, reaching the state's highest point at Hoye Crest on Backbone Mountain, 3,360 feet, near the West Virginia border in Garrett County. The state's geography ranges from that mountainous west to the tidewater lowlands of the Eastern Shore and the Atlantic beaches around Ocean City Maryland.

Verified against Wikipedia, September 2026.

Climate Patterns

Maryland's climate varies with its geography, generally humid subtropical in the lowlands around the Chesapeake Bay and Eastern Shore, shifting toward a cooler, more continental pattern in the Appalachian west. Summers are hot and humid across the bay region and the Baltimore-Washington corridor, with high humidity driven by the bay itself; winters there are relatively mild, with occasional snow and ice. It is rare for the surface of the Chesapeake Bay to freeze, something that last happened in the winter of 1976-77.

Western Maryland, rising into the Appalachians around Deep Creek Lake and Garrett County, sees a markedly colder and snowier winter, supporting skiing at the Wisp Resort, while summers there are milder than the lowlands. The state occasionally feels the edge of coastal storms and hurricanes moving up the Atlantic seaboard, and in 2011 a magnitude-5.8 Virginia earthquake was felt moderately throughout Maryland. Spring and fall bring the mildest, most reliable weather statewide.

Habitats & Biodiversity

The Chesapeake Bay is Maryland's dominant ecosystem: the largest estuary in the United States, fed by more than 150 rivers and streams across a six-state drainage basin, and home to over 300 species of fish along with extensive shellfish and crab populations, though nutrient pollution and urban runoff have degraded water quality and reduced yields since the mid-20th century. Assateague Island, a barrier island shared with Virginia, adds marshes, coves and dune ecosystems along the Atlantic side of the Delmarva Peninsula, entirely protected as a national seashore.

Western Maryland's Appalachian forests and the Catoctin and South Mountains support a different ecology, forested ridge-and-valley terrain that carries part of the Appalachian Trail. In 2007, Forbes rated Maryland the fifth-greenest state in the country, and the state joined the Regional Greenhouse Gas Initiative that year, though invasive species like kudzu and Japanese stiltgrass remain a pressure on native plant communities across the state.

Wildlife & Birds

Assateague Island's feral horses, generally called Assateague ponies on the Maryland side and Chincoteague ponies in Virginia, are the state's best-known wildlife: around 80 live within the Maryland portion of Assateague Island National Seashore, managed as wild animals apart from contraceptive treatments to control the herd's size. The Chesapeake Bay itself sustains the Maryland blue crab, the state's largest commercial fishery and official state crustacean, alongside more than 300 fish species and significant oyster beds; the Chesapeake Bay Retriever, first recognized as a distinct breed by the American Kennel Club in 1878, was developed here as a waterfowl-hunting dog suited to the bay's cold water.

The bay's marshes and shoreline attract abundant waterfowl and shorebirds, and its waters occasionally see unusual visitors, a male manatee returned to the bay repeatedly between 1994 and 2011, well north of the species' normal range. Western Maryland's forests support the more typical Appalachian wildlife of white-tailed deer, black bear and wild turkey, though the Chesapeake Bay's fisheries and shorebird populations remain the ecological centerpiece of the state.

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Checked against Wikipedia — Maryland is a state in the Mid-Atlantic and Southeastern regions of the United States, It borders Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east, as well as with the Atlantic Ocean to its…, With a total area of {{Convert|12407|sqmi|km2}}, Maryland is the ninth-smallest state by land area, and its population of 6.1 million ranks it the 19th-most…, One of the original Thirteen Colonies, the charter for the Province of Maryland was petitioned and secured in 1632 by George Calvert, 1st Baron Baltimore…, In 1760, Maryland's current boundaries took form following the settlement of a long-running border dispute with Pennsylvania, The U.S. state of Maryland has a varied geography, It has an area of {{convert|12407|sqmi}} and is comparable in overall area with Belgium, It is the 42nd largest and 9th smallest state and is closest in size to the state of Hawaii, Maryland borders Pennsylvania to the north, Delaware to the northeast, the Atlantic Ocean to the east, and to the west and south by West Virginia and Virginia, The Chesapeake Bay nearly bisects the state and the counties east of the bay are known collectively as the Eastern Shore, The highest point in Maryland, with an elevation of {{Convert|3360|ft|m}}, is Hoye Crest on Backbone Mountain, in the southwest corner of Garrett County, The Chesapeake Bay is the largest estuary in the United States, More than 150 major rivers and streams flow through the bay's drainage basin, which covers parts of six states ... and all of Washington D.C., The bay is approximately {{convert|200|mi|abbr=on}} long from its northern headwaters in the Susquehanna River to its outlet in the Atlantic Ocean, The bay is spanned twice, in Maryland by the Chesapeake Bay Bridge from Sandy Point (near Annapolis) to Kent Island, the bay has become 'emptier', with fewer crabs, oysters and watermen (fishermen) since the mid-20th century, Situated on the Chesapeake Bay at the mouth of the Severn River, Annapolis is a historic city with a strong maritime culture, Due to overfishing and environmental pressures some of the fisheries have seen declining yields, especially in the Chesapeake Bay fishery, Smith Island is a collection of three distinct island communities ... on the Chesapeake Bay, The island is the last inhabited island in Maryland that is not accessible by car, The island's population is approximately 220, down from a peak of about 800, The Chesapeake and Ohio Canal ... operated from 1831 until 1924 along the Potomac River between Washington D.C., and Cumberland, Maryland, the canal had an elevation change ... which required 74 canal locks, 11 aqueducts ... and the Paw Paw Tunnel, The Chesapeake Bay is home to over 300 species of fish and numerous shellfish and crab species, including the blue crab, A herd of around 150 ponies are maintained on the Virginia side of the fence, and 80 on the Maryland side, Callinectes sapidus, commonly known as the blue crab, is Maryland's largest commercial fishery and has been designated its state crustacean, The eastern half of Maryland, on the Atlantic Coastal Plain, has a humid subtropical climate (Köppen Cfa) with hot, humid summers and a cool to cold winter (September 2026).