Lance Cpl. Vince Walls, a mortarman with Lima Company, 3rd Battalion, 25th Marine Regiment, adjusts a M224 60mm Mortar during Exercise Northern Strike at Camp Grayling, Mich., Aug. 7, 2018. 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 Cpl. Niles Lee)