Illinois River

American lotus blooms on the waters along the Illinois River
American lotus blooms on the waters along the Illinois River

The Illinois River is a principal tributary of the Mississippi River and flows approximately 273 miles (439 km) long, through the state of Illinois. The river drains a large section of central Illinois, with a drainage basin of 40,000 square miles (104,000 km²). Because it serves as the principal water route between the Mississippi River and the Great Lakes, the Illinois River was important among Native Americans and early European traders. After the construction of the Illinois and Michigan Canal and the Hennepin Canal in the 19th century, the river’s role as link between Lake Michigan and the Mississippi was extended into the era of modern industrial shipping. Today, the Illinois River still serves as an important route for barge navigation, water recreation and provides for domestic and industrial uses for neighboring communities.

Scientists have studied the geology and biology of the Illinois River for over 100 years-leading some to call it the “most studied river in the world” (Riverweb Museum Consortium, 2003). From 1905 to 1915, more freshwater fish were harvested from the Illinois River than from any other such river in the U.S., except for the Columbia River in Washington State. In 1950, flocks of migrating mallards and lesser scaup ducks numbered two million along the Illinois, making it a hunter’s paradise. Just after the turn of the present century, the Illinois briefly sustained a fleet of 2,600 boats harvesting mussels for the booming pearl button industry.

Today’s hunters and commercial fishermen cannot match those historic harvests. The long-term sustainability of the river’s biological harvest was hampered by a succession of ecological injuries, including the draining of wetlands, channelization of tributaries, disconnection with the floodplain, the diversion of Chicago domestic and industrial waste, construction and maintenance of the navigation channel and more intensive, chemical-reliant and top-soil depleting agriculture.

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