Maryland Route 246 (MD 246) is a state highway in the U.S. state of Maryland. Known for most of its length as Great Mills Road, the state highway runs from MD 5 in Great Mills east to the entrance to Naval Air Station Patuxent River (NAS Patuxent River) just east of the highway's intersection with MD 235 in Lexington Park. In conjunction with MD 5, MD 246 connects NAS Patuxent River and the suburban area surrounding the military base with Leonardtown. The state highway was originally constructed around 1920. MD 246 extended east onto land now occupied by NAS Patuxent River to serve a ferry from St. Mary's County to the southern end of Calvert County. The ferry was discontinued and the state highway's eastern terminus was rolled back to MD 235 when NAS Patuxent River was constructed during World War II; the remainder of MD 246 was upgraded as a military access project. MD 246 was expanded to a multi-lane highway in the 1990s.
