Iron Brigade Memorial Highway | ||||
US 12 highlighted in red | ||||
Route information | ||||
Maintained by IDOT and CDOT | ||||
Length | 85.14 mi[1] (137.02 km) | |||
Existed | 1928[2]–present | |||
Major junctions | ||||
West end | ![]() | |||
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East end | ![]() ![]() ![]() | |||
Location | ||||
Country | United States | |||
State | Illinois | |||
Counties | McHenry, Lake, Cook | |||
Highway system | ||||
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U.S. Route 12 (US 12) in the U.S. state of Illinois is an arterial highway that runs northwest to southeast through the Chicago metropolitan area. It enters Illinois at the Wisconsin border north of Richmond, and exits into Hammond, Indiana, from Chicago near the foot of the onramp to the Indiana Toll Road (Interstate 90, or I-90); as it exits Illinois, the route is also concurrent with US 20 and US 41. Within Illinois, US 12 runs for a distance of 85.14 miles (137.02 km).[1]