Mason Neck NWR
Mason Neck National Wildlife Refuge
Ecology and Management
Elizabeth Hartwell Mason Neck National Wildlife Refuge (NWR) is part of the Potomac River NWR Complex in northern Virginia, 14 miles from Washington, D.C. It was established in 1969 as the first NWR specifically created to protect an endangered species, the Bald Eagle. The main impoundment on the site (Little Marsh) still frequently hosts foraging Bald Eagles, as well as other fish-eating species (Weller 2011). Little Marsh also contains one of the largest Great Blue Heron rookeries in Virginia. Other breeding species include Least Bittern, Black-crowned Night-heron, Wood Duck and Hooded Merganser. Water level management includes drawing levels down as low as possible in June and July to improve foraging conditions for young Bald Eagles and Great Blue Herons. Sedimentation and encroachment of woody vegetation have been recurring management challenges in the impoundments.
“In the past, large storms have overtopped the dike threatening to damage or wash it out.”
The Little Marsh and Little Marsh Road impoundments both occur on a tidal river (the Potomac), but as they are both essentially dammed tributaries, they may be most susceptible to overtopping due to flooding during large rainfall events.
“Mason Neck Refuge is located within driving distance of approximately 10 million residents of Virginia, Maryland, and Washington, D.C.”
– (Weller 2011)
Approximately 19,000 people per year visit Mason Neck NWR, but foot and boat access is currently prohibited at both impoundments to avoid disturbing sensitive species.