Conowingo Dam encompasses the area north of a line beginning at point, at or near Lat. 39° 39.762' N., Long. 76° 9.605' W., then running 227° (True) to a point, at or near Lat. 39° 39.245' N., Long. 76° 10.320' W., and south of a line beginning at a point, at or near Lat. 39° 40.197' N., Long. 76° 10.483' W., then running 199° (True) to a point, at or near Lat. 39° 39.438' N., Long. 76° 10.812' W. Vessels are prohibited in this area all year.