The Traverse Gap is an ancient river channel occupied by Lake Traverse, Big Stone Lake, and the valley connecting them at Browns Valley, Minnesota. It is on the border of the U.S. states of Minnesota and South Dakota. Traverse Gap has an unusual distinction for a valley: it is transected by a continental divide, and in some floods, water has flowed across that divide from one drainage basin to the other. Before the Anglo-American Convention of 1818, it marked the border between British territory in the north and U.S.—or, earlier, French—territory in the south.