Illinois Waterway, 336 mi (541 km) long, linking Lake Michigan with the Mississippi River, N Ill.; an important part of the waterway connecting the Great Lakes with the Gulf of Mexico. The Illinois Waterway extends from the mouth of the Chicago River, on Lake Michigan, following the Chicago Sanitary and Ship Canal, the lower Des Plaines River, and the Illinois River to the Mississippi at Grafton, Ill. The Calumet channels branch southeast from the waterway and link it with the Calumet industrial region along the Ill.-Ind. border. Principal cargoes, carried chiefly by barges, are coal, petroleum, and grain products. Recreational areas have been developed along the waterway.