September 21, 2016 - Lance Cpl. Patrick Butner, machinegunner with 2nd Battalion, 4th Marine Regiment, attached to 31st Marine Expeditionary Unit, mans an M240B machine gun position while participating in an exercise to secure Orote Airfield on U.S. Naval Base Guam during Exercise Valiant Shield. VS16 is a biennial field exercise with a primary focus on interoperability and integration of joint training among U.S. forces. (Image created by USA Patriotism! from U.S. Marine Corps photo by U.S. Navy Mass Communication Specialist 1st Class John Johnson)