Big Muddy River Big Muddy River The Big Muddy River is a river in southern Illinois. It joins the Mississippi River just south of Grand Tower. The Big Muddy has been dammed near Benton, forming Rend Lake. The Big Muddy has a mud bottom for most of its length. The Big Muddy drains a watershed. In 1995, water quality was assessed as "fair" to "good". Pollution sources include agricultural practices, mining and municipalities. The watershed of the Big Muddy was covered by the Illinoian Glacier about 300,000 to 132,000 years before present. The Big Muddy basin formed after the retreat of that glacier.
Big Sandy Creek (Illinois) two streams combine shortly before discharging into the Illinois River opposite the hamlet of Montezuma, Illinois. Sand discharged by the alluvial creeks may have helped form McEvers Island, a silt island in the Illinois River just below the mouth of the creek. Big Sandy Creek (Illinois) Big Sandy Creek, often called the "Big Branch", is a tributary of the Illinois River in central Illinois. It drains a large portion of southwestern Morgan County and southern Scott County. The drainage of Big Sandy Creek includes Lake Jacksonville and the county seat of Scott County, Winchester, Illinois. Most of the Big Sandy