Along the C&O Canal shoreline of the river there are only freshwater mollusks because the Potomac is a freshwater source.
Did You Know?
George Washington's dream of connecting the eastern states with the western frontier led to the creation of the Patowmack Company. Locks were built around unnavigable parts of the Potomac River for improved commerce. The C&O Canal inherited the right of way after the Patowmack Company's demise.