U.S. Marine Corps Lance Cpl. Tyler Varias, a mortar man, with Weapons Company, 1st Battalion, 25th Marine Regiment, 4th Marine Division, Marine Forces Reserve, participates in Exercise Northern Strike 17 at Camp Grayling Joint Maneuver Combat Center, Michigan from July 29 to Aug. 12, 2017. Exercise Northern Strike is a National Guard Bureau-sponsored training exercise that unites service members from multiple branches, states and coalition countries to conduct combined ground and air combat operations. (U.S. Marine Corps photo by Lance Cpl. Imari J. Dubose/Released).