Bing found the following results
Potomac River - Wikipedia
Potomac, Maryland - Wikipedia
Potomac River | Maryland, Virginia, Washington DC, & Map
Potomac River - American Rivers
Potomac River - WorldAtlas
A Guide to the Potomac River - Washingtonian
History & Culture - Potomac Heritage National Scenic Trail (U.S ...
Potomac Heritage National Scenic Trail (U.S. National Park Service)
101 River Facts — Potomac Conservancy
RiverExplorer - Potomac River Guide