U.S. Air Force Airmen from the 570th Contingency Response Group at Travis Air Force Base, Calif., guard the group compound at Geronimo Landing Zone on Fort Polk, La., Oct 18, 2012. The Green Flag exercise, held at the Joint Readiness Training Center, is conducted on a monthly basis. During the most recent Green Flag exercise, Airmen from the 317th Airlift Group participated in a joint-service environment May 13-22, providing Dyess mobility Airmen the opportunity to refine processes and procedures that can potentially enhance real-world operations effectiveness.. (U.S. Air Force photo/Tech. Sgt. Parker Gyokeres)