Mill Creek is a stream in Washington and St. Francois counties of eastern Missouri. [1] It is a tributary of the Big River. The stream source is located at: 37°56′29″N 90°43′25″W / 37.94139°N 90.72361°W near Mineral Point and the confluence with Big River is at: 38°02′10″N 90°37′11″W / 38.03611°N 90.61972°W just south of Blackwell. [1] [2] [3]