Starting Monday, the Michigan Department of Transportation will be investing $4.9 million to rebuild four bridges in Iron and Ontonagon counties. Work will include deck replacement, substructure repairs, scour countermeasures, beam end repairs, steel cleaning and coating, and roadway approach work on M-64 over the Floodwood River, M-64 over Halfway Creek, US-141 over the East Branch of the Net River, and US-45 over Roselawn Creek.