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
Dorchester County, Maryland Dorchester County, Maryland Dorchester County is a county located in the U.S. state of Maryland. As of the 2010 census, the population was 32,618. Its county seat is Cambridge. The county was formed in 1669 and named for the Earl of Dorset, a family friend of the Calverts (the founding family of the Maryland colony). Dorchester County comprises the Cambridge, MD Micropolitan Statistical Area, which is also included in the Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Statistical Area. It is located on the Eastern Shore of Maryland. Dorchester County is the largest county on the Eastern Shore. It is bordered by the Choptank