Rohrersville is a census-designated place in Washington County, Maryland, United States. The population was 175 at the 2010 census. The first settlers to arrive in the vicinity of Rohrersville began to survey land tracts in the 1730s. "Park Hall," a tract of 1,550 acres, encompassing the present village of Rohrersville, was patented in 1732 by William Park…Rohrersville is a census-designated place in Washington County, Maryland, United States. The population was 175 at the 2010 census. The first settlers to arrive in the vicinity of Rohrersville began to survey land tracts in the 1730s. "Park Hall," a tract of 1,550 acres, encompassing the present village of Rohrersville, was patented in 1732 by William Parks, and resurveyed in 1766 to Andrew Grimm.