mouth_of_the_watercourse machipongo river
The ___MASK83___ is an estuary lying inland from the ___MASK67___ , and surrounded by the North American mainland to the west , and the Delmarva Peninsula to the east . It is the largest such body in the contiguous United States . The northern bay is within Maryland , the southern portion within Virginia , and is a very important feature for the ecology and economy of those two states , as well as others . More than 150 major rivers and streams flow into the bay ' s drainage basin , which covers parts of six states ( New York , Pennsylvania , Delaware , Maryland , Virginia and West Virginia ) plus all of the District of Columbia . The Machipongo River is a 16 . 5 - mile - long ( 26 . 6 km ) river in Accomack County on the Eastern Shore of the U . S . state of Virginia . Virginia (, officially the Commonwealth of Virginia ) is a state located in the Mid - Atlantic region of the United States , as well as in the historic Southeast . Virginia is nicknamed the " Old Dominion " due to its status as the first colonial possession established in mainland British America , and " Mother of Presidents " because eight U . S . presidents were born there , more than any other state . The geography and climate of the Commonwealth are shaped by the Blue Ridge Mountains and the ___MASK83___ , which provide habitat for much of its flora and fauna . The capital of the Commonwealth is Richmond ; Virginia Beach is the most populous city , and Fairfax County is the most populous political subdivision . The Commonwealth ' s estimated population is over 8 . 3 million , which is slightly less than New York City . The Blue Ridge Mountains are a physiographic province of the larger Appalachian Mountains range . This province consists of northern and southern physiographic regions , which divide near the ___MASK55___ gap . The mountain range is located in the eastern United States , starting at its southernmost portion in Georgia , then ending northward in Pennsylvania . To the west of the Blue Ridge , between it and the bulk of the Appalachians , lies the Great Appalachian Valley , bordered on the west by the Ridge and Valley province of the Appalachian range .