Mason Neck State Park is located in Fairfax County, Virginia. The park is on a peninsula formed by Pohick Bay on the north, Belmont Bay on the south and the Potomac River to the east, which was once known as "Dogue Neck" but now as "Mason Neck". The park adjoins the Elizabeth Hartwell Mason Neck National Wildlife Refuge and encompasses 1,814 acres. It is home to bald eagles, great blue herons, ospreys, and many other types of wildlife.