Project Blue Book – UFO Investigations

UFO sightings were reported in various countries around the world, including the United States. Sightings reported to the authorities by U.S. citizens are included in this record collection, which was created by the U.S. Air Force between June 1947 and December 1969. Individual case files contain reports from UFO observers, correspondence between these observers and the Air Force, newspaper and magazine clippings, and analyses of photographs and other physical evidence (although files rarely include photos or physical evidence).

Project Blue Book Status Report, 1952 ( photo)
Project Blue Book Status Report, 1952 ( photo)

While a small number of sighting reports were submitted by telegram, most were submitted on an official Air Force questionnaire that contains name and address of the observer(s), hour and date of the sighting, prevailing weather conditions, and a description of what the observer(s) saw. Some observers included a drawing of the UFO. Each case file contains a control sheet that summarizes the sighting report and provides the official Air Force explanation for the sighting.

Names and addresses of people involved in the sightings are redacted from these case files (exception—sightings reported by military personnel). The case files are arranged chronologically, then by state, territory, or country, and then by city or town.

Note: This record collection includes multiple case files from Missouri and Illinois sightings, so I can cheerfully report that the little green (or gray, depending on the observer) men sent in the probes in this area as enthusiastically as they did anywhere else! To find these case files, just use (not case-sensitive) either of these search terms:


You can use at Central Library or any of our branches. You can also use it in your command module if you have a valid SLPL card and PIN.

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