Students from several U.S. Army units and a U.S. Air Force unit head up a hill on a several-mile ruck march while wearing snowshoes to a bivouac site during the Fort McCoy, Wis. Cold-Weather Operations Course on the fort's southern training area Jan. 13, 2022. The CWOC is modeled after the Cold-Weather Leader Course taught by the Army Northern Warfare Training Center at Black Rapids, Alaska. (U.S. Army Reserve photo by Sgt. 1st Class Clinton Wood).