The FBI Vault (vault.fbi.gov) hosts the Bureau’s complete UFO/paranormal FOIA library. Key collections: UFO Files Parts 1-16 (FBI’s investigation role 1947-1954, working with USAF). Roswell Dallas Teletype (July 8, 1947): FBI Dallas Field Office reported “flying disc resembling a high altitude weather balloon” found near Roswell — the Bureau’s official description of their first awareness of the incident. Guy Hottel Memo (March 22, 1950): Head of FBI Washington Field Office reported to Director J. Edgar Hoover that an Air Force investigator described three recovered flying saucers in New Mexico — circular, 50-foot diameter, raised centers, each containing three 3-foot-tall humanoid bodies in metallic cloth, bandaged like speed pilot suits. The memo states the saucers were found because “the government has a very high-powered radar set-up in that area and it is believed the radar interferes with the controlling mechanism of the saucers.” Majestic 12 files (1988): Two FBI offices received similar MJ-12 memos. Files are stamped “BOGUS” — the FBI itself declared these documents fraudulent. NICAP correspondence (1957-1969). Animal/Cattle Mutilation files (1974-1978). The Hottel Memo became the FBI Vault’s most-viewed document ever — over 1 million views.