<P> Illinois is in the midwestern United States . Surrounding states are Wisconsin to the north , Iowa and Missouri to the west , Kentucky to the south , and Indiana to the east . Illinois also borders Michigan , but only via a northeastern water boundary in Lake Michigan . Nearly the entire western boundary is the Mississippi River , except for a few areas where the river has changed course . Illinois ' southeastern and southern boundary is along the Wabash River and the Ohio River . Whereas , its northern boundary and much of its eastern boundary are straight survey ( longitudinal and latitudinal ) lines . Illinois has a maximum north - south distance of 390 miles ( 630 km ) and 210 miles ( 340 km ) east - west . Its total area is 57,918 square miles ( 150,010 km ) . </P>
<P> Illinois is in the midwestern United States . Surrounding states are Wisconsin to the north , Iowa and Missouri to the west , Kentucky to the south , and Indiana to the east . Illinois also borders Michigan , but only via a northeastern water boundary in Lake Michigan . Nearly the entire western boundary is the Mississippi River , except for a few areas where the river has changed course . Illinois ' southeastern and southern boundary is along the Wabash River and the Ohio River . Whereas , its northern boundary and much of its eastern boundary are straight survey ( longitudinal and latitudinal ) lines . Illinois has a maximum north - south distance of 390 miles ( 630 km ) and 210 miles ( 340 km ) east - west . Its total area is 57,918 square miles ( 150,010 km ) . </P>
what river is the western border of the state illinois
what river is the western border of the state illinois
the Mississippi River
the Mississippi River