Potomac River

Potomac River, U.S. river flowing through Washington, D.C. Formed by the confluence of the 110-mi (177-km) long northern branch and the 140-mi (125-km) long southern branch, it flows 287 mi (462 km) into Chesapeake Bay. Navigation for large ships is prevented above Washington, D.C., by the Great Falls. The river is noted for its scenic attraction.