Project 10073 Record Card — Pueblo, Colorado, 14 June 1958

On June 14, 1958, at 10:46 MST, a Weather Bureau observer in Pueblo, Colorado, reported an unidentified aerial object while conducting a routine pilot balloon observation using a theodolite. The witness, who possessed 28 years of experience in the Weather Bureau, described the object as circular with an apparently flat ring and a rounded dome in the middle, resembling a picture of Saturn. The object appeared white or silvery-white, lacked any metallic luster, and produced no sound, smoke, or vapor trails. It was observed moving from the northeast to the southwest at a high rate of speed, estimated to be at least 500 mph, and was positioned above cirrus clouds, which were estimated at 30,000 feet. The observer tracked the object for approximately five minutes until it disappeared into the haze. The report was forwarded through the Air Research and Development Command to the Air Technical Intelligence Center. Internal military correspondence indicates that the sighting was treated as a complex case. Analysts performed checks against satellite schedules and radar data, all of which returned negative results. The object was ruled out as a balloon or a known satellite, with one analyst noting that the theodolite used was of too low a power to resolve the object if it were a satellite, and that the movement did not match known satellite trajectories. The final assessment by the Air Technical Intelligence Center concluded that, assuming the observer was reliable and the sighting was not an optical artifact, the event remained a valid 'UNKNOWN'. The documentation includes the original record card, the observer's detailed summary, and subsequent routing slips between military intelligence personnel discussing the scientific validity of the report.