The Choptank River encompasses all the waters of the Choptank River and its tributaries upstream of a line beginning at Blackwalnut Point, at or near Lat. 38° 40.200' N., Long. 76° 20.350' W., then running 134° (True) to Cooks Point, at or near Lat. 38° 37.867' N., Long. 76° 17.217' W., excluding the Tred Avon River, beginning at a point at or near Lat. 38° 40.250' N., Long. 76° 11.867' W., then running 73° (True) to a point, at or near Lat. 38° 40.550' N., Long. 76° 10.617' W., and Tuckahoe River, beginning at a point at or near Lat. 38° 48.828' N., Long. 75° 53.887' W., then running 42° (True) to a point at or near Lat. 38° 48.927' N., Long. 75° 53.772' W.