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. M-28 is the longest state trunkline with the "M-" prefix at 290 miles (467 km). Three sections of the highway are part of the Lake Superior Circle Tour, and two sections carry memorial highway designations. M-28 passes through forested woodlands, bog swamps, and urbanized areas. Sections of roadway cross the Ottawa National Forest and both sections of the Hiawatha National Forest. Other landmarks accessible from the highway include the Seney National Wildlife Refuge and several historic bridges. M-28 dates to the 1919 formation of the state's trunkline system, though the original highway was much shorter. It was expanded eastward to the Sault Ste. Marie area in the late 1920s.
