Interstate 39 is an interstate highway in the midwestern United States. It goes from Normal, Illinois at Interstate 55 to Wausau, Wisconsin.

Length

Major cities along the route

• Normal, Illinois
• Rockford, Illinois
• Madison, Wisconsin

Intersections with other Interstates

• Interstate 55 in Normal, Illinois
• Interstate 80 in La Salle, Illinois
• Interstate 88 in Rochelle, Illinois
• Interstate 90 in Rockford, Illinois. They stay joined until Portage, Wisconsin
• Interstate 43 in Beloit, Wisconsin
• Interstate 94 in Madison, Wisconsin. They stay joined for 30 miles.

Spur routes

None

Notes

• Future plans call for Interstate 39 to be extended north from Wausau to Merrill, Wisconsin along the U.S. Highway 51 freeway, which is Interstate standard, but it was not signed as Interstate as of December 2001.

• I-39 in Plover, Wisconsin is home to the Good and Evil Watertowers (off-site link).

• The southern terminus of I-39 in Normal, Illinois is very close (about two miles) to Interstate 74.

• I-39 is the owner of the Illinois version of the Abraham Lincoln Memorial Bridge, which spans the Illinois River in north central Illinois.

• For all but one of the 139 miles (224 km) that Interstate 39 is in Illinois, it is multiplexed with U.S. Highway 51.