MDOT has highlighted five historic bridges along the route of M-28 on the MDOT website. In Interior Township, Ontonagon County, the highway crosses the Ontonagon River over a bridge built in 1929. Designed by the State Highway Department and built by the firm of Meads and Anderson, the Ontonagon River Bridge is one of only three steel arch bridges in Michigan. The main span arch is long. A former routing of M-28 in Covington Township crosses the Rock River. Although this section was bypassed by a new alignment of the trunkline in 1924, the bridge remains complete "with corbeled bulkheads and six panels recessed in the concrete spandrel walls." The corbels and spandrels are decorative features found in the concrete sides of the bridge.