The Des Plaines River is a river that flows southward for through southern Wisconsin and northern Illinois in the United States Midwest, eventually meeting the Kankakee River west of Channahon to form the Illinois River, a tributary of the Mississippi River.Native Americans used the river as transportation route and portage. When French explorers and missionaries arrived in the 1600s, in what was then the Illinois Country of New France, they named the waterway La Rivière des Plaines (River of the Plane Tree) as they felt that trees on the river resembled the European plane tree. The local Native Americans showed these early European explorers how to traverse waterways of the Des Plaines watershed to travel from Lake Michigan to the Mississippi River and its valley.