U.S. Route 12 in Minnesota

From the South Dakota state line at Ortonville, to Orono in Minneapolis–Saint Paul, US 12 is mostly a rural two-lane highway with a 60-mile-per-hour (97 km/h) posted speed limit, with slower speed limits through towns and a four-lane surface arterial segment through the city of Willmar. From Orono to Wayzata, US 12 is a two-lane freeway/super-two bypass around Long Lake. From western Wayzata to Interstate 394 (I-394) in Minnetonka, US 12 is a six-lane freeway, with a posted speed limit of 65 mph (105 km/h). East of I-494 in Minnetonka, US 12 is invisibly concurrent with I-394 and I-94 through Minneapolis and Saint Paul to the Wisconsin state line at Hudson.

Legally, the Minnesota section of US 12 is defined as unmarked Constitutional / Legislative Routes 149, 26, and 10 in Minnesota Statutes §§ 161.115(80) and 161.114(2). US 12 is not marked with these legislative numbers along the actual highway.

US 12 was established on November 11, 1926.[2] In 1929, the only sections paved were between Litchfield and Willmar and between Wayzata through Minneapolis–Saint Paul to Wisconsin.[3] The entire route was paved by 1940.[3] Beginning in the 1950s, older sections of US 12 that ran through city centers were replaced with bypasses.[4]

From 2006 to 2008, the US 12 two-lane freeway bypass was constructed through Orono and Long Lake. The new bypass ties into the existing US 12 freeway at the western edge of Wayzata.