Lark, UtahOctober 1950

On October 11, 1950, a worker at the Lark Tunnel in Lark, Utah saw an unusual object cross the night sky. The man, a compressor operator, was working at approximately 2210 hours (10:10 p.m.) when he and a companion spotted what he first thought was a meteor. Upon closer observation, he changed his mind.

The object appeared as a long, thin line of fire racing across the sky at extremely high speed. As he watched, the line of fire widened out. Then it seemed to dip, and what looked like an explosion occurred. The front end of the object broke away from the main body, which stayed visible in the sky before suddenly fading completely from view. The witness estimated the object was about 40 or 50 miles away, somewhere in the vicinity of the Provo River, roughly southwest of his position.

The witness did not report the incident immediately. He called the 115th CIC Detachment (a U.S. Army intelligence unit) six days later, on October 17, 1950. When asked why he had waited, he explained that he wasn't sure which agency should handle such a report. An Air Force officer who received the account noted in writing that no investigation had been initiated by his office and was simply passing the information along to headquarters.

The Air Force evaluated this sighting as a meteor. The complete case file is reproduced below as held by the National Archives, spanning 7 pages.