Lt. Col. Timothy Christison, 90th Medical Support Squadron commander, takes notes during a group activity at the 20th Air Force Senior Leader Conference on F.E. Warren Air Force Base, Wyo., March 30, 2017. Squadron commanders within the command networked and discussed ways to improve mission execution and the quality of life for their Airmen. The 20th AF SLC focused on revitalizing the squadron as a core fighting unit, a major focus area of Gen. David L. Goldfein, Air Force Chief of Staff. (U.S. Air Force photo by 1st Lt Veronica Perez)