30 Miles NW Lake Meade, NevadaJune 1947

On June 28, 1947, a U.S. Air Force pilot flying a P-51 fighter plane northeast of Las Vegas spotted five or six white circular objects in the sky. The pilot, a lieutenant stationed at Brooks Field in Texas, was heading toward Portland, Oregon, cruising at 10,000 feet and flying at 285 miles per hour on a northwesterly course when he noticed the objects at his four o'clock position (to his right). The objects appeared to be at about 6,000 feet altitude and moving on a heading of 120 degrees at an estimated speed of 280 miles per hour.

The pilot said the objects flew smoothly and maintained a tight formation. He estimated each one was about 76 inches (roughly 6 feet) in diameter. He was confident they were not birds because they closed in on his position very quickly, and he ruled out conventional aircraft or jets because of his experience flying both types.

An Air Force investigator interviewed the pilot on July 14, 1947, and noted that he seemed sincere and matter-of-fact. The pilot made no wild claims and drew no firm conclusions about what he had seen.

The Air Force analyzed the sighting and concluded the objects were probably a cluster of balloons, possibly carrying cosmic ray detection equipment. Since the pilot's plane was traveling on a course of 300 degrees and the objects appeared to be on a course of 120 degrees, the investigator reasoned that the relative motion the pilot observed might have been an optical illusion created by his own plane's movement. The case file does not provide a final official determination beyond this balloon hypothesis.

The full case file is reproduced below as held by the National Archives across six pages of microfilm.