 First designated by July 1 , 1919 along a different routing , M @-@ 47 was extended several times in both directions through the 1920s and 1930s . Two of these extensions replaced sections of M @-@ 111 in the Bay City area . At the apex of its length in the 1950s , M @-@ 47 stretched from Webberville in the south to Bay City State Park in the north . Since Interstate 75 ( I @-@ 75 ) opened in the Tri @-@ Cities area , the northern section of M @-@ 47 was rerouted and truncated as a result of related changes to other highways . The southern end was moved after I @-@ 96 opened in the Lansing area . Further changes into the 1970s shortened M @-@ 47 more , producing the routing in use today . 
