TRAVIS AIR FORCE BASE, Calif. -- After more than 33 years of faithful service to her country, Chief Master Sgt. Denise P. Butler, Superintendent, 349th Aerospace Medicine Squadron, celebrates her many years of service during a ceremony held in her honor at Travis Air Force Base, Calif. on April 7, 2013. (U.S. Air Force photo / Senior Airman Amelia Leonard)