M-12 is a former state highway in the Upper Peninsula of Michigan. It was replaced in 1926 by:
Since 1926, M-12 north of the St. Ignace area has been replaced by:
^ Michigan Center for Geographic Information (May 2007). "Geographic Data Library" . Michigan Department of Information Technology . Retrieved February 27, 2008 .
^ Michigan State Highway Department (July 1, 1919). State of Michigan (Map). Scale not given. Lansing: Michigan State Highway Department. Upper Peninsula sheet. OCLC 15607244 . Retrieved December 18, 2016 – via Michigan State University Libraries.
^ Bureau of Public Roads & American Association of State Highway Officials (November 11, 1926). United States System of Highways Adopted for Uniform Marking by the American Association of State Highway Officials (Map). 1:7,000,000. Washington, DC: U.S. Geological Survey . OCLC 32889555 . Retrieved November 7, 2013 – via Wikimedia Commons .
^ Michigan State Highway Department (December 1, 1926). Official Highway Condition Map (Map). [c. 1:823,680]. Lansing: Michigan State Highway Department.