Mississippi river
The Mississippi River forms the western boundary of the State of Illinois.
The Mississippi River forms the western border of Illinois.
The Mississippi River forms the western boundary of Illinois.
Missisippi
The Mississippi river forms the boundary between Missouri and Illinois!
Two rivers partially form Illinois State's Eastern boundary. The Wabash River is one river that forms Illinois' boundary. The Ohio River is the other river that forms the state's boundary.
Mississippi river
Illinois is bordered by the Mississippi River on the west.
The Mississippi River forms the western border of Illinois.
The Wabash is the longest river in Indiana. It flows from Ohio across northern Indiana until it forms the border between Indiana and Illinois.
The Colorado River.
The Mississippi River forms the wavy western border of Illinois. And the Ohio Wabash River is the southern border of Illinois.