Potomac Park is an unincorporated subdivision and census-designated place located on the North Branch Potomac River in Allegany County, Maryland, United States. As of the 2010 census, it had a population of 2,530. Potomac Park lies along U.S. Route 220 between Cresaptown and Cumberland. The CDP of Bowling Green is immediately to the north …Potomac Park is an unincorporated subdivision and census-designated place located on the North Branch Potomac River in Allegany County, Maryland, United States. As of the 2010 census, it had a population of 2,530. Potomac Park lies along U.S. Route 220 between Cresaptown and Cumberland. The CDP of Bowling Green is immediately to the north on Route 220.