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
Interstate 295 (Maryland–District of Columbia) Interstate 295 (Maryland–District of Columbia) Interstate 295 (I-295) in the U.S. state of Maryland and in Washington, D.C. is a spur route connecting I-95 / I-495 and Maryland Route 210 (Indian Head Highway) near the Potomac River (just outside the District's boundary with Maryland) to Interstate 695 & D.C. Route 295 in the Anacostia neighborhood of Washington, DC. Although I-295 technically begins at the Capital Beltway (I-95/I-495), a pair of mainline ramps connects the southern terminus of the route to the nearby MD 210. Continuing north from this interchange, I-295 enters the District of Columbia; the route is only long