M.28 a.k.a. M-28 is an east–west state trunkline highway that almost completely traverses the Upper Peninsula in the U.S. state of Michigan, from Wakefield to near Sault Ste. Marie in Bruce Township. Along with US Highway 2, M-28 forms a pair of primary highways linking the Upper Peninsula from end to end, providing a major access route for traffic from Michigan and Canada along the southern shore of Lake Superior. M-28 is the longest state trunkline in Michigan numbered with the "M-" prefix at 290.373 miles. The entire highway is listed on the National Highway System, while three sections of M-28 are part of the Lake Superior Circle Tour. M-28 also carries two memorial highway designations along its route.