FBI agents reported seeing a black triangular object hover silently above a mountain ridge before suddenly accelerating at a speed comparable to a fighter jet, according to newly released Department of War documents on unidentified anomalous phenomena (UAP).

The 2026 sighting is one of several incidents covered in the records. Others include decades-old military encounters, reports of mysterious creatures, unexplained lights and what one witness believed was a portal at a Utah ranch.

The FBI report describes a dark, nonreflective, triangular object that resembled a drone. Its wingspan was estimated at 9 to 15 feet, and it showed no visible exhaust or conventional propulsion. The agents said it rose vertically above a ridgeline and then accelerated into a canyon without making any sound.

A separate report from the Pentagon's All-domain Anomaly Resolution Office (AARO) gives a fuller account. It describes a matte-black object that climbed roughly 200 to 300 feet above the ridgeline, hovered for about 20 seconds, and then seemed to accelerate almost instantly, vanishing into the canyon within two to three seconds. Witnesses saw no engines, rotors or exhaust. Using handheld thermal equipment, the agents also observed a uniform heat signature across the object's surface, without the concentrated hot spots usually linked to propulsion.

The Pentagon report notes that the speed was estimated by witnesses rather than measured by instruments. The two documents also differ on duration: the FBI described a sighting of about three seconds, while AARO detailed around 10 seconds of vertical ascent, 20 seconds of hovering and a further two to three seconds of rapid flight. Neither report identifies the object or its origin. Fox News Digital has asked AARO whether it has since been identified and whether images released with the FBI report show the actual encounter or are illustrations.

The files also include an Air Force intelligence report dated Jan. 19, 1957, on an unidentified radar contact involving a U.S. B-52 bomber on a Strategic Air Command mission near Saudi Arabia. Flying at about 39,000 feet on Jan. 18, the bomber detected a target roughly 6,000 yards away. It stayed on the radar screen for five to seven minutes before disappearing as the aircraft turned left. Investigators noted that no other aircraft were expected in the area but acknowledged the change in direction may have caused the contact to vanish.

Other historical records concern sightings near California's Santa Catalina Island. On June 25, 1952, three Boy Scouts at summer camp reported a silent, silver object moving faster than a conventional jet while they hiked. They said it made a climbing turn and then appeared to disintegrate, according to an Air Force intelligence report. Investigators noted the scouts had no instruments to gauge speed or altitude and that their limited experience made their account difficult to assess. A March 15, 1955, report describes a witness near Avalon who saw a bright, round object change from orange to red before falling straight down. The Air Force classified it as a "probable meteor."

The release also contains a 60-page investigation carried out in 2010 by Bigelow Aerospace Advanced Space Studies at a Utah ranch associated with reports of unexplained phenomena. Investigators interviewed residents who described towering dog-like creatures walking on two legs and mysterious balls of light. Other witnesses reported smaller hairy creatures, a prehistoric-looking bird and a worm said to be 8 feet long. One witness described a transparent, rippling structure she believed was a portal to another world.

The investigation used eyewitness sketches, surveillance cameras, environmental monitoring and hair samples taken from areas tied to creature sightings. Laboratory testing showed the hair came from ordinary animals, including domestic dogs and a raccoon. The report did not establish that the alleged creatures or other extraordinary phenomena exist. Fox News Digital has also contacted the FBI for comment.