The Colorado River.
The Columbia River
The Mississippi River forms the western border of Illinois.
Mississippi.
Mississippi river
Illinois is bordered by Wisconsin to the north.
Illinois.
Ohio
The US State of Illinois and the US State of Kentucky share a border with the Ohio River that runs between the two States. There is no land border with each other.
The Illinois River is entirely contained within the State of Illinois.
Indiana
How many driving miles is it from the Indiana border to the Iowa border crossing the state of Illinois?