Formed by the confluence of the Ohio and Upper Mississippi, the Lower Mississippi is defined as the portion of the river downstream from Cairo, IL. It flows through portions of Missouri, Kentucky, Tennessee, Arkansas, Mississipi, and Louisiana
The Upper Mississippi comprises 914 miles (1,471 kilometers) from St. Anthony Falls, Minnesota, to the confluence with the Ohio River at Cairo, Illinois. It flows through portions of Missouri, Illinois, Iowa, Wisconsin and Minnesota.