the Mississippi River
The Mississippi River forms the western border of Illinois.
The Mississippi River forms the western border of Illinois.
The Mississippi River forms the wavy western border of Illinois. And the Ohio Wabash River is the southern border of Illinois.
The river that forms the western border of Illinois is the Mississippi River.
The Mississippi River.
Illinois is bordered by the Mississippi River on the west
Mississippi River
The Mississippi River forms the Western border of the States of Illinois, Tennessee, and Mississippi. The Mississippi River forms the Eastern border of the States of Iowa, Missouri, Arkansas, and Louisiana.
The Wabash River forms the southern portion of Indiana's western border. The northern portion of Indiana's western border is simply a straight line marked on the map. The southern border of Indiana is also a river - the Ohio.
Illinois is bordered by the Mississippi River on the west.
The Wabash is the longest river in Indiana. It flows from Ohio across northern Indiana until it forms the border between Indiana and Illinois.
Mississippi.