Potomac River
The Nation’s River, flowing past Washington to Chesapeake Bay
George Washington was born near the Potomac, built Mount Vernon on its bank and chose a site on its tidal reach for the national capital, which is why the river is often called the Nation's River. It runs about 383 miles (616 km) from the Fairfax Stone in the Allegheny Mountains of West Virginia to Chesapeake Bay at Point Lookout, Maryland, draining 14,670 square miles (38,000 km²) of West Virginia, Maryland, Virginia, Pennsylvania and the District of Columbia. Its name comes from Patawomeck, an Algonquian village on its southern bank.
The river crosses every landscape of the Mid-Atlantic. It slices through the Blue Ridge at Harpers Ferry, where the Shenandoah joins it, then tumbles 76 feet (23 m) over Great Falls and through Mather Gorge as it crosses the fall line. Below Little Falls it becomes tidal, widening past Washington and Alexandria into an estuary 11 miles (17 km) wide at its mouth. Since the Washington Aqueduct opened in the 1860s, the river has been the capital region's main source of drinking water.
The Potomac is also a boundary with an unusual history. Under the 1877 Black-Jenkins Award, Maryland owns the river bank to bank to the low-water mark on the Virginia shore, while Virginia keeps the right to use its water. The C&O Canal towpath follows the Maryland bank for 184.5 miles (297 km) from Georgetown to Cumberland. Since 1940 the four basin states and the District have coordinated their use of its water through the Interstate Commission on the Potomac River Basin.