Frederick County, Maryland Frederick County, Maryland Frederick County is located in the northern part of the U.S. state of Maryland. As of the 2010 U.S. Census, the population was 240,336. The county seat is Frederick. Frederick County is included in the Washington-Arlington-Alexandria, DC-VA-MD-WV Metropolitan Statistical Area. Like other outlying sections of the Washington metropolitan area, Frederick County has experienced a rapid population increase in recent years. It borders the southern border of Pennsylvania and the northeastern border of Virginia. The county is home to Catoctin Mountain Park (encompassing the presidential retreat Camp David) and to the U.S. Army's Fort Detrick. It has also
Maryland Route 214 MD 214 is a part of the National Highway System as an intermodal connector between the Addison Road Metro station and the Capital Beltway. The highway is a National Highway System principal arterial from Southern Avenue to the Addison Road Metro station, from the Capital Beltway to US 301, and from Vicksburg Road near Davidsonville to Shoreham Beach Road in Beverley Beach. Central Avenue from Washington east to Edgewater was planned as one of the original state roads laid out by the Maryland State Roads Commission in 1909. This road followed most of MD 214's present alignment from Capitol Heights