Much of the Baltimore–Washington corridor lies just south of the Piedmont in the Coastal Plain, There are numerous man-made lakes, the largest of them being the Deep Creek Lake, a reservoir in Garrett County in westernmost Maryland.
Maryland has shale formations containing natural gas, where fracking is theoretically possible.
Maryland's reptile and amphibian population includes the diamondback terrapin turtle, which was adopted as the mascot of University of Maryland, College Park.
Close to the small town of Hancock, in western Maryland, about two-thirds of the way across the state, there are 1.83 miles (2.95 km) between its borders.
This geographical curiosity makes Maryland the narrowest state, bordered by the Mason–Dixon line to the north, and the northwards-arching Potomac River to the south.
Maryland possesses a variety of topography within its borders, contributing to its nickname America in Miniature.
It ranges from sandy dunes dotted with seagrass in the east, to low marshlands teeming with wildlife and large bald cypress near the Chesapeake Bay, to gently rolling hills of oak forests in the Piedmont Region, and pine groves in the Maryland mountains to the west.
Maryland's state flower, the black-eyed susan, grows in abundance in wild flower groups throughout the state.