Busiest domestic routes from TUS (January 2016 – December 2016)[32] Rank City Passengers Carriers 1 Dallas/Fort Worth, Texas 274,000 American 2 Los Angeles, California 231,000 American, Delta, Southwest, United 3 Phoenix–Sky Harbor, Arizona 176,000 American 4 Denver, Colorado 171,000 Southwest, United 5 Las Vegas, Nevada 121,000 Southwest 6 Atlanta, Georgia 99,000 Delta 7 Chicago–O'Hare, Illinois 84,000 American, United 8 San Diego, California 78,000 Southwest 9 Houston–Intercontinental, Texas 71,000 United 10 Chicago–Midway, Illinois 68,000 Southwest