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).

Marines parachute from an CH-47 Chinook helicopter during Exercise Northern Strike 17 over Camp Grayling Joint Maneuver Training Center, Mich., Aug. 2, 2017. The Marines are assigned to Echo Company, 4th Reconnaissance Battalion, 4th Marine Division, Marine Forces Reserve. Northern Strike 17 prepares Marines for Integrated Training Exercise 2018 and future mobilizations and deployments. Marine Corps photo by Lance Cpl. Imari J. Dubose

CAMP GRAYLING, Mich. – A U.S. Marine with Echo Company, 4th Reconnaissance Battalion, 4th Marine Division, Marine Forces Reserve executes High Altitude–High Opening techniques at Camp Grayling Joint Maneuver Training Center, Michigan on August 2, 2017 during Exercise Northern Strike 17. The high-altitude, high-opening parachute insertion method allows Marines to covertly insert themselves onto the battlefield to conduct reconnaissance, acting as the eyes and ears for the commander. 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).