More than 150 rivers and streams flow into the bay 's 64,299 square miles ( 166,534 km2 ) drainage basin , which covers parts of six states ( New York , Pennsylvania , Delaware , Maryland , Virginia , and West Virginia ) and the District of Columbia .
The bay 's watershed covers 64,299 square miles ( 166,534 km2 ) in the District of Columbia and parts of six states : New York , Pennsylvania , Delaware , Maryland , Virginia , and West Virginia .