UFO Sighting Report — Pleasant Hill, California, October 1958

This document details the investigation of a UFO sighting reported by a 29-year-old chemist in Pleasant Hill, California, on the evening of October 8, 1958. The witness, while stargazing, observed a hazy, orange, dumbbell-shaped object moving rapidly across the sky from the west toward the southeast. The witness estimated the object's duration of visibility at approximately 15 seconds, noting that it moved faster than a low-flying airplane and made sharp turns. The witness explicitly stated that the object made no sound and appeared to be self-propelled, though they noted it did not resemble any aircraft they had previously seen. The report includes a detailed questionnaire completed by the witness, along with correspondence between the witness, the local Weather Bureau, and the Air Technical Intelligence Center (ATIC). The Air Force conducted an investigation into the report, which included checking with the 755th ACW and the Army Aviation Section. The Air Force concluded that the object was likely an H-37 helicopter, noting that the witness's description of an engine on each side of the fuselage matched the H-37's design. The report includes internal routing slips, teletype messages, and formal letters from Colonel H. K. Gilbert and Major Lawrence J. Tacker to the witness, confirming the official determination that the sighting was an H-37 helicopter operating in the San Francisco area.