The Grand River is one of three major tributaries of Lake Michigan, including the Fox River (Green Bay tributary) on the western shore, and Kalamazoo River on the southeastern shore. It falls in elevation from 1260 ft. in the highlands of its headwaters to 577 ft. at its mouth on Lake Michigan. Its waters drain northward through the lake, then south and east through the Great Lakes waterways into the St. Lawrence River, which flows northeasterly into the Gulf of St. Lawrence on the Atlantic Ocean. The Grand River discharges an average 3,800 ft³/s (107.5 m³/s).