  m-66 is a northâsouth state trunkline highway on the lower peninsula (lp) of the us state of michigan. it runs from the indiana state line in the south to charlevoix in the north. m-66 is the only state highway to traverse almost the entire northâsouth distance of the lp. it starts as a continuation of state road&nbsp;9 (sr&nbsp;9) which provides access to the indiana toll road. the total length is , which includes  of freeway between interstate 94 (i-94) and downtown battle creek designated as i-194. one section of the highway is an expressway, a type of divided limited access highway, while the section along i-194 is a full freeway, otherwise m-66 is a two-lane rural highway. two sections are listed on the national highway system. the first usage of the m-66 designation dates back to around july 1, 1919 with the rest of the original state highway system. at the time, the highway only extended between lowell and lakeview, a route now covered by m-91. the highway has been lengthened in a series of extensions north and south starting in 1925. a rerouting in 1944â45 removed m-66 from its original 1919 routing to replace another hi
State_highways_in_Michigan Transportation_in_Antrim_County,_Michigan Transportation_in_Barry_County,_Michigan Transportation_in_Branch_County,_Michigan Transportation_in_Calhoun_County,_Michigan Transportation_in_Charlevoix_County,_Michigan Transportation_in_Eaton_County,_Michigan Transportation_in_Ionia_County,_Michigan Transportation_in_Kalkaska_County,_Michigan Transportation_in_Mecosta_County,_Michigan Transportation_in_Missaukee_County,_Michigan Transportation_in_Montcalm_County,_Michigan Transportation_in_Osceola_County,_Michigan Transportation_in_St._Joseph_County,_Michigan