The State Trunkline Highway System was created on May 13, 1913, by an act of the Michigan Legislature; at the time, one of the system's divisions corresponded to the initial segment of M-140. Division 5 followed a course from Niles northward to Mackinaw City that encompassed the highway between Watervliet and South Haven. In 1919, the Michigan State Highway Department (MSHD) signposted the highway system for the first time, and the future M-140 corridor was assigned to part of the original M-11. On November 11, 1926, M-11 was redesignated as part of US 31 in the state.