M-17 is an original state trunkline dating back to the 1919 signing of the system. On July 1, 1919, the highway started at M-11 in Berrien County in the southwestern Lower Peninsula and ran east to Detroit. The debut of the U.S. Highway System replaced most of M-17 with two different highways. From Watervliet to Ann Arbor, US 12 replaced M-17; east of Ypsilanti to Detroit, US 112 replaced M-17. The M-17 designation also replaced M-23 on Ecorse Road between Ypsilanti and Lincoln Park and then ran concurrently with US 25 into Detroit. The Ann Arbor segment was rerouted along Boulevard Drive (now Stadium Boulevard) between US 12 and US 23.