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 US 31. Division 5 followed a course from Niles northward to Mackinaw City. In 1919, the Michigan State Highway Department (MSHD) signposted the highway system for the first time, and the future US 31 corridor was assigned two numbers. From the state line north through Niles to St. Joseph, it carried the original M-58 designation and from there northward it was the original M-11.