Delaware Geography: The Land

Geography and Landforms of Delaware

The state of Delaware consists of two major land regions: The Piedmont and the Atlantic Coastal Plain.

Delaware is our second smallest state. It is only 96 miles long and ranges from 9 to 35 miles in width.

Delaware is made up of these Physiographic Areas

Mid-Atlantic Coastal Plain

The Mid-Atlantic Coastal Plain extends from the Atlantic Ocean, south of Long Island, to the Fall Line, where the hilly Piedmont begins. It is arbitrarily separated from the South Atlantic Coastal Plain at the Virginia-North Carolina border (with the exception of the Great Dismal Swamp in the southeast corner of Virginia, which is grouped in the southern area). The area was formed by shifting sea levels and alluvial deposition from rivers draining mountains to the west. Water continues to be a dominant feature of the landscape, creating forested wetlands and salt marsh and shaping barrier island and bay complexes. Upland forests on the remaining land graded in composition from pine dominated areas on the outer Coastal Plain (nearer the coast) to hardwood forests on the inner Coastal Plain. This was the site of the first successful English settlement in North America, and the natural landscape has been altered by European culture for nearly four centuries. The current human population approaches 11 million and is expected to continue to expand into the future, placing ever-increasing demands on the region's natural resources.

Northern Ridge and Valley

The Northern Ridge and Valley extends from southeastern Pennsylvania, through northwestern New Jersey and southeastern New York nearly to the base of the Adirondack Mts. It includes portions of several major river valleys, including the Hudson, Delaware, and Susquehanna Rivers. Ecologically, this is a transitional area, with forested ridges grading from primarily oak-hickory forests in the south to northern hardwood forests further north. Pine-oak woodlands and barrens and hemlock ravine forests are also important along ridges, whereas bottomland and riparian forests are important in the valleys, which are now largely cleared for agricultural and urban development. Roughly 50% of the physiographic area is forested today, the vast majority occurring at higher elevations. About 40% of the area is in agricultural production, primarily a mixture of dairy pastureland and corn. Over 200,000 ha is state forest land in PA and NJ; other important public lands include High Point State Park (NJ) and Wallkill National Wildlife Refuge.

Delaware Landscape and Landforms:

The Piedmont

An area of gently rolling hills found in the northwest corner of the state, is 10 miles wide at its widest point. The highest point in Delaware, just 450 feet above sea level, is found in the Piedmont.

Atlantic Coastal Plain

The Atlantic Coastal Plain stretches across the rest of the state, a low, flat region that rises only about 80 feet above sea level. A 30,000-acre swamp lies along southern boundary of the state. A long sand bar -- 28 miles long -- forms a border with the Atlantic Ocean. This sandy strip to the east is a popular vacation region.