Washington County, Maryland Washington County, Maryland Washington County is located in the western part of the U.S. state of Maryland. As of the 2010 census, the population was 147,430. Its county seat is Hagerstown. Washington County was the first county in the United States to be named for the Revolutionary War general (and later President) George Washington. Washington County is one of three Maryland counties recognized by the Appalachian Regional Commission as being part of Appalachia. The county borders southern Pennsylvania to the north, Northern Virginia to the south, and the Eastern Panhandle of West Virginia to the south and west. Washington County
Maryland Route 4 Maryland Route 4 Maryland Route 4 (MD 4) is a state highway in the U.S. state of Maryland. The highway runs from MD 5 in Leonardtown north to Southern Avenue in Suitland at the District of Columbia boundary, beyond which the highway continues into Washington as Pennsylvania Avenue. MD 4 is a four- to six-lane highway that connects Washington and communities around the Capital Beltway (Interstate 95 and I-495) with southern Prince George's County with southwestern Anne Arundel County. The highway is the primary highway for the length of Calvert County, during most of which the route runs concurrently with