M-11 was an original Michigan state trunkline (map) following the West Michigan Pike auto trail along the east shore of Lake Michigan.
In 1926, the U.S. Highway system was created, superseding M-routes in most cases (possibly with a transitional period between the old and new routes). This first iteration of M-11 was taken over in Berrien County by US-12 from the Indiana line to St. Joseph, US-12 and US-31 from there northeastward to Watervliet, then US-31 northward from there.
Chris Bessert's Michigan Highways: M-11
This page created Monday July 2, 2007 / Last revised July 2, 2007