The crew of Coast Guard Cutter Mackinaw powers the cutter through a 3-foot thick wall of ice as it exits the Soo Locks in Sault Ste. Marie, Mich., March 21, 2014. The Mackinaw along with the Coast Guard Cutters Katmai Bay and Morro Bay passed through the locks together en route to breaking ice in the St. Marys River and Lake Superior in preparation of the scheduled opening of the locks, March 25. (U.S. Coast Guard photo by Petty Officer 2nd Class Levi Read)