Hamilton Field, California UFO Sighting (September 9, 1947) — FBI Files

Background

On September 9, 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

A memorandum from Lt. Colonel Hubbard details an investigation into reports of ‘flying discs’. The document appears to be a transmittal of information regarding the investigation to the FBI. No specific observations are detailed on this page, only the initiation of an inquiry.

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.

Sources

• Original release on war.gov
• Department of War UFO Disclosure Portal
• AARO (All-domain Anomaly Resolution Office)