ATLAS-I, known as Trestle, was a Cold War electromagnetic pulse testing facility at Sandia National Laboratories near Kirtland Air Force Base in Albuquerque, New Mexico, built from 1972 to 1980 for the U.S. Air Force. Using powerful Marx generators and an enormous mostly wooden test structure, it exposed full-size aircraft and missiles to intense non-nuclear pulses that simulated the effects of high-altitude nuclear explosions. At its peak it was the world’s largest non-nuclear EMP generator and a major center for studying radiation hardening of military systems. The program ended in 1991, but the site remained significant as a rare relic of Cold War research and as a foundation for later Sandia pulsed-power work.