CAMP GRAYLING, Mich. – A Sikorsky SH-60 Seahawk with Helicopter Sea Combat Squadron 22, departs after inserting U.S. Marines with Echo Company, 4th Reconnaissance Battalion, 4th Marine Division, Marine Forces Reserve into Lake Margrethe, Camp Grayling Joint Maneuver Training Center, Michigan on July 31, 2017. Reserve Marines are using this airborne technique, which is also used by small units and special operations for insertion into military areas of operations. 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).