U.S. Marine Force Reserve Cpl. Carlos Elizarraras,

U.S. Marine Force Reserve Cpl. Carlos Elizarraras, 4th Medical Battalion, prepares to mount a M240B machine gun to a High Mobility Multipurpose Wheeled Vehicle (HMMWV) during Combat Support Training Exercise (CSTX) 86-17-02 at Fort McCoy, WI., August 15, 2017. CSTX includes more than 12,000 service members from the Army, Navy, Air Force, and Marine Corps as well as from six countries. CSTX is a large-scale training event where units experience tactical training scenarios specifically designed to replicate real-world missions. (U.S. Army photo by Spc. Cody Hein/Released)