Along the C&O Canal shoreline of the river there are only freshwater mollusks because the Potomac is a freshwater source.
Did You Know?
Canal historians estimate approximately 35,000 laborers helped dig the canal as well as build aqueducts, culverts, locks, lock houses, etc. It took 22 years to build the canal from Georgetown, DC to Cumberland, MD. Much of the workforce were immigrants from Ireland and western Europe.