U.S. Marine Corps Reservist Lance Cpl. Sean Knox,

U.S. Marine Corps Reservist Lance Cpl. Sean Knox, Headquarters and Service Company, 4th Medical Battalion, takes cover beside a U.S. Army Reserve M113 Armored Personnel Carrier driven by 1st. Lt. Casey Reidy, Headquarters and Headquarters Company, 397th Engineer Battalion, 372nd Engineer Brigade, 416th Theater Support Command, as they react to a complex attack during Combat Support Training Exercise 86-16-03 (CSTX 86-16-03) on Fort McCoy, Wis., Aug. 22, 2016. Nearly 9,000 service members from across the country are participating in CSTX 86-16-03 hosted by the 86th Training Division and the 84th Training Command’s third and final CSTX of the year. (U.S. Army Reserve Photo by Sgt. 1st Class Clinton Wood).