Mason Neck is a peninsula jutting into the Potomac River in Fairfax County, Virginia, southwest of Washington, D.C..

It comprises an area of 20.0 square miles (51.8 km2),[1] two-thirds of which is preserved as parkland by regional, state, and national authorities.

In 1969, local residents and conservation groups achieved the establishment of the Elizabeth Hartwell Mason Neck National Wildlife Refuge, with the specific objective of protecting the bald eagle.

The Mason Neck land that was traded to the county later became a state-controlled nature reserve called Meadowood.

[4][5] Birds include great blue herons, Canada geese, ospreys, wood ducks, teal, owls, and woodpeckers.