It retains noteworthy biodiversity .
At the same time , because it is the southernmost Potomac River freshwater estuary in Maryland , Mattawoman has escaped much of the degradation associated with urbanization spreading from Washington , D.C.
freshwater estuary retains noteworthy biodiversity .
At the same time , because it is the southernmost Potomac River freshwater estuary in Maryland , Mattawoman has escaped much of the degradation associated with urbanization spreading from Washington , D.C.