Cpl. Mark Hickok patrols through a field during a clearing mission in Marja. U.S. Marine Corps Cpl. Mark Hickok patrols through a field during a clearing mission in Marja in Afghanistan's Helmand province on April 9, 2011. Hickok, a combat engineer, is assigned to the 1st Combat Engineer Battalion. SHARE: Download: Full Size (0.09 MB) Credit: VIRIN: 232677-V-CHY55-651.jpg Photo Gallery