The Coast Guard Cutter Mackinaw, a 240-foot Icebreaker homeported in Cheboygan, Mich., approaches the Duluth Arial Lift Bridge near Duluth, Minn., just after sunrise, March 17, 2013. The cutter was in the area to break ice in preparation for the beginning of the shipping season. (U.S. Coast Guard photo by Petty Officer 1st Class Nathan Poppink)