M-12 is a former state highway in the Upper Peninsula of Michigan. It was replaced in 1926 by: * U.S. Highway 2 in Michigan (US 2) between the state line at Ironwood and Crystal Falls * M-69 between Crystal Falls and Sagola * M-45 between Sagola and Iron Mountain (now M-95) * US 2 between Iron Mountain and Sault Ste. Marie Since 1926, M-12 north of the St. Ignace area has been replaced by: * Business Loop Interstate 75 through St. Ignace * County Road H-63 to the Rogers Park area * M-134 to Cedarville * M-129 to Sault Ste. Marie * Business Spur Interstate 75 in Sault Ste. Marie