Air Intelligence Information Report: Unidentified Aerial Object, Oakridge, Tennessee, 7 December 1951

On December 7, 1951, at 0815 EST, a contractor guard employed by the Union Carbon and Carbide Company at the K-25 Gaseous Diffusion Plant in Oakridge, Tennessee, reported observing an unidentified aerial object. The witness, described as an honest and conscientious individual with 20/70 vision and no reported eye trouble, observed the object for a total of two minutes. The object was described as a square, grey-white, smooth, non-shiny entity, approximately twenty feet wide, resembling a piece of canvas. It exhibited no markings, protrusions, or ridges, and produced no sound, smoke, or trail. The object was observed rising and descending three times between a ridge and the cloud level (approximately 6,000 feet). It also performed a circular maneuver and moved both with and against prevailing winds. The observer reported that the object rose straight up, descended to within 300 feet of the ridge, and eventually disappeared into the clouds after a final rising maneuver at a 20-degree angle. The security section at the plant initially treated the incident as a ground-based event, sending patrols to investigate. Because the object was not initially reported as airborne, Ground Controlled Interception (GCI) was not notified until 1002 EST. By the time two F-47 aircraft were dispatched to the area, the object had disappeared, and no interception was made. The official intelligence assessment, prepared by Captain Robert K. Hall of the 30th Air Division, suggests that while the observer likely saw something, their estimates regarding the object's speed and distance of travel were in error, as the reported performance would have been extreme. The report concludes with no definitive identification of the object.