Project Blue Book Case #3166. On August 15, 1954, witnesses in San Marcos, Texas, observed a bright object in the sky. San Marcos was home to Gary Air Force Base, a helicopter pilot training facility — one of the few bases dedicated to rotary-wing aviation training in the early 1950s.
San Marcos sits along the Balcones Escarpment between Austin and San Antonio, in the transition zone between the Texas Hill Country and the coastal plain. The area's clear skies and moderate terrain made it ideal for helicopter training operations, and Gary AFB's personnel were experienced aviators accustomed to low-altitude observation.
August 1954 was during a moderate period of Blue Book activity. The object over San Marcos could not be identified despite checks with Gary AFB flight operations and civilian traffic. The case was classified "Unknown."