Illinois River 20 miles (32 km) of its course, the Illinois is separated from the Mississippi River by only about five miles, by a peninsula of land that makes up Calhoun County. The Illinois joins the Mississippi near Grafton, approximately 25 miles (40 km) northwest of downtown St. Louis and about 20 miles upstream from the confluence of the Missouri River and the Mississippi. South of Hennepin, the Illinois River is following the ancient channel of the Mississippi River. The Illinoian Stage, about 300,000 to 132,000 years ago, blocked the Mississippi near Rock Island, diverting it into its present channel. After the
Big Rib River Big Rib River The Big Rib River is a river in central Wisconsin. It originates in northeastern Taylor County at Rib Lake, and flows into Marathon County where it joins the Wisconsin River. "Rib River" is a translation of the Native American name. The Big Rib River flows through Rib Falls then to Marathon City, before it converges into the Wisconsin River at the northeast face of Rib Mountain. The Dells of the Big Rib River, below Goodrich, are believed to be the rapids where Father René Menard disappeared in 1661, which attempting to reach a band of Huron Indians