Howard County is a county located in the central part of the U.S. state of Maryland. As of the 2010 census, the population was 287,085. Its county seat is Ellicott City. Howard County is included in the Baltimore-Columbia-Towson, MD Metropolitan Statistical Area, which is also included in the Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Statistical Area. However, recent development in the south of the county has led to some realignment towards the Washington, D.C. media and employment markets. The county is home to Columbia, a major planned community of approximately 100,000 founded by developer James Rouse in 1967.