Hamilton Field, California UFO Sighting (July 30, 1947) — FBI Files
A first saucer wave case from Hamilton Field, California. On July 30, 1947, the FBI was instructed to investigate reported sightings of flying discs to determine if they were genuine, imaginary, or hoaxes.
Background
On July 30, 1947, in Hamilton Field, California, U.S. government investigators recorded an unidentified-object incident later released to the public on May 8, 2026 as part of the Presidential Unsealing and Reporting System for UAP Encounters (PURSUE). The incident is one of the first wave of “flying saucer” reports that swept the United States after the Kenneth Arnold sighting of June 1947 and the Roswell incident of July 1947. The case was filed with the Federal Bureau of Investigation, whose Knoxville, Albuquerque, Los Angeles, and other field offices routed UFO reports to headquarters under the Bureau’s standing protocols for the protection of vital installations.
What the document records
On July 30, 1947, the FBI was instructed to investigate reported sightings of flying discs to determine if they were genuine, imaginary, or hoaxes. The investigation aimed to ascertain if individuals with Communist sympathies were behind the sightings to incite fear of a secret Russian weapon. The Bureau’s investigation found no evidence of subversive involvement in the reported sightings.
The number of witnesses is not specified in the released document.
Type of case
The case is a visual sighting reported by ground or air observers.
Status
All records released under the PURSUE program are designated unresolved by the All-domain Anomaly Resolution Office (AARO) by default. The federal government has not concluded that the events were anomalous, has not concluded that they were conventional, and has not ruled out either possibility. Conventional candidates for sightings of this period include experimental aircraft, weather balloons (especially the Project Mogul series in the late 1940s), atmospheric optical phenomena such as sundogs and lenticular clouds, and astronomical objects including Venus, the Moon, and meteors near the horizon.