 The highway was rerouted in a few places in the 1950s, and the last new segment shifted in 1973 near Kalkaska.M-72 starts its trans-peninsular journey at M-22 in the community of Empire on the shores of Lake Michigan in the Sleeping Bear Dunes National Lakeshore.From there it runs easterly uphill through mixed farmland and forest to cross the base of the Leelanau Peninsula.