Project 10073 Record Card and UFO Report — Rapid City, South Dakota, 4 August 1958

On August 4, 1958, at 1624Z, a UFO sighting occurred in Rapid City, South Dakota. The event involved a single, round or disc-shaped white object, estimated to be the size of a basketball held at arm's length. One observer reported a halo effect surrounding the object. The object was observed for 5 to 10 seconds, traveling in a straight and level path before disappearing instantaneously to the south. The observers, who included a Captain from the 77th Bombardment Squadron, were described as sincere and highly impressed by the sighting, though they initially hesitated to report it for fear of ridicule. The Intelligence Division of the 28th Bombardment Wing conducted an investigation, contacting all observers and querying the 74th AC&W, the local control tower, and the 54th FIS. All radar inquiries yielded negative results. The official conclusion reached by the investigating authorities was that the sighting was likely caused by a turning aircraft at a greater distance than the observers estimated. The position of the sun was noted as being in the proper location to highlight a banking aircraft, which would account for the visual characteristics reported by the witnesses. The report notes that while the observers were aware of aircraft in the area, they remained convinced the object was not a conventional aircraft due to its extreme speed, which one witness estimated at approximately one thousand knots.