Illinois River

The Illinois River (Miami-Illinois: Inoka Siipiiwi[5]) is a principal tributary of the Mississippi River and is approximately 273 miles (439 km) long. Located in the U.S. state of Illinois,[6] the river drains a large section of central Illinois, with a drainage basin of 28,756.6 square miles (74,479 km2).[7] The drainage basin extends into Wisconsin, Indiana, and a very small area of southwestern Michigan.

The river was important among Native Americans and early French traders as the principal water route connecting the Great Lakes with the Mississippi. The French colonial settlements along these rivers formed the heart of the area known as the Illinois Country in the 17th and 18th centuries. After the construction of the Illinois and Michigan Canal and the Hennepin Canal in the 19th century, the role of the river as link between Lake Michigan and the Mississippi was extended into the era of modern industrial shipping. The Illinois now forms the basis for the Illinois Waterway.