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). - 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).

CAMP GRAYLING, Mich. – U.S. Marines from Echo Company, 4th Reconnaissance Battalion, 4th Marine Division, Marines Forces Reserve, check their gear after conducting a helocast exercise into Lake Margrethe at Camp Grayling Joint Maneuver Training Center, Michigan, during exercise Northern Strike 2017, July 31, 2017. Northern Strike 17 prepares Marines from across 4th Marine Division as they prepare for Integrated Training Exercise 2018 and future mobilizations and deployments. (U.S. Marine Corps photo by Lance Cpl. Niles Lee/Released) - CAMP GRAYLING, Mich. – U.S. Marines from Echo Company, 4th Reconnaissance Battalion, 4th Marine Division, Marines Forces Reserve, check their gear after conducting a helocast exercise into Lake Margrethe at Camp Grayling Joint Maneuver Training Center, Michigan, during exercise Northern Strike 2017, July 31, 2017. Northern Strike 17 prepares Marines from across 4th Marine Division as they prepare for Integrated Training Exercise 2018 and future mobilizations and deployments. (U.S. Marine Corps photo by Lance Cpl. Niles Lee/Released)