Pentagon Files Detail Silent Black Triangle That Hovered Over Secret US Site With No Exhaust Or Visible Engine

Newly released US government files describe how federal agents reportedly saw a silent, black triangular objectrise above a ridge, hover in the air, and disappear into a canyon at a sensitive national security site in the western United States. Yet two official records sharply disagree on how long the object was visible, and no video or physical evidence has been released to show what it was.

According to a report from NHI Anomalous, the documents formed part of the seventh release of records under the Pentagon's Presidential Unsealing and Reporting System for UAP Encounters (PURSUE), published on 23 October. The release contained 28 documents, all in PDF format, according to the report.

The records concern unidentified anomalous phenomena (UAP), the term US authorities use for objects or events they cannot immediately explain. An unexplained sighting does not, by itself, prove that an object has an extraordinary or extraterrestrial origin.

Two Official Files, Two Different Timelines

One document, an Airborne Anomaly Resolution Office (AARO) memorandum identified as DOW-UAP-D176, describes a matte-black triangular object with an estimated wingspan of 13 to 15 feet. It reportedly climbed vertically for about 10 seconds, hovered for around 20 seconds, and then descended into a canyon in a rapid manoeuvre lasting two to three seconds.

The memorandum says witnesses detected no sound, exhaust, visible seams, or control surfaces. It also describes a thermal signature — the heat detected from an object — that appeared consistent across its surface.

A second record, an FBI interview document identified as FBI-UAP-D043, contains the agents' account of the same sighting. It describes an object resembling a delta-wing drone, with an estimated wingspan ranging from nine to 15 feet.

The most significant difference concerns the duration. The AARO memorandum describes a sequence lasting more than 30 seconds, while the FBI document says the entire sighting lasted approximately three seconds.

The FBI account also refers to the object as an unmanned aerial system, a term commonly used for a drone. Neither document, as described by NHI Anomalous, establishes that this identification was confirmed.

The records therefore leave an important question unresolved: whether the discrepancy reflects different recollections, differences in how the reports were prepared, or another explanation.

Images Recreate the Event Rather Than Capture It

The FBI document includes nine images that might initially appear to show the object moving through the sky. However, NHI Anomalous reports that the images are not photographs of the triangle itself.

Instead, they use the same photograph of a mountain ridge, with a black shape added at different positions to illustrate the witnesses' description of its movement. The images are a visual reconstruction rather than footage captured during the incident.

That distinction matters because the released material does not provide direct photographic or video evidence of the object. According to the report, the agents were observing the area at dusk and could not quickly reposition their main optical and tripod-mounted sensors, which were pointed in another direction.

They reportedly used binoculars and a handheld thermal device. The object disappeared from the thermal device's view when it accelerated, according to the account.

A search of the canyon the following morning reportedly found no wreckage, ground scarring or damaged vegetation.

Wider PURSUE Files Go Beyond One Black Triangle

The black triangle was not the only subject covered by the latest release. According to NHI Anomalous, the documents also include historical reports of unidentified objects, contractor records concerning investigations at a Utah ranch associated with unusual sightings, and accounts of unidentified radar contacts.

One laboratory report in the release examined four hair samples collected during investigations at the ranch. NHI Anomalous says the results identified one sample as raccoon and three as carrying a genetic sequence commonly found in domestic dogs.

The findings offer a conventional explanation for those particular samples, but they do not resolve every claim associated with the location.

Key Questions Still Hang Over the Black Triangle Case

For the black-triangle case, the central evidence remains witness testimony recorded in two government documents. The accounts share several details but disagree on the duration of the sighting and how the object was characterised.

The documents do not establish what the object was, and no instrumented speed measurement was obtained, according to NHI Anomalous. Claims that it travelled at a specific speed should therefore not be treated as confirmed measurements.

For now, the newly released files provide more detail about what the agents said they saw — but they do not settle the mystery.