The Tremonton and Great Falls Film Analysis

The Tremonton film analysis is a 1953 US Navy study of two UFO films — one shot in Utah in July 1952, one in Montana in 1950 — carried out by the Navy's photographic interpretation specialists at the request of the Air Force. Its conclusion was that the objects were most likely self-luminous light sources of a kind the analysts could not identify as either natural phenomena or known man-made objects, and that birds, aircraft and balloons were ruled out. The report was declassified on 7 August 2026.

These two films are not new. They have been argued over for seventy years and both are freely available online. What is new is the Navy's own working: the measurements, the methods, the g-forces, and the flat sentences in which trained image analysts said they could not account for what they were looking at.

Who Analysed the Films, and Why That Matters

The report came from the US Naval Photographic Interpretation Center, the organisation that would later become the National Photographic Interpretation Center — the outfit that read the U-2 imagery during the Cuban Missile Crisis. Its job was to look at photographs of things and work out what they were, usually with a foreign military at the other end of the question.

The Air Force asked for the work in the autumn of 1952. The Photogrammetry Division took it, produced a first report that December, and then a fuller one on 4 May 1953 signed by the Officer in Charge and sent to the Director of Naval Intelligence. This second report supersedes the first and is the one now public.

The report is also candid about its own limits, in a way that reads well seventy years on. It states that "because of the lack of proper equipment, money and personnel, the investigation was limited", and it asks for further tests. It is a working document, not a proclamation.

The Two Films: Tremonton and Great Falls

One detail in the report is a quiet reminder of how nearly this evidence was lost. The original Utah film arrived "in very poor condition; dry, brittle", and had to be duplicated with colour correction before anyone could work on it. What survives, and what everyone has argued about since, is a copy of a copy.

How the Navy Measured a UFO Film in 1953

There were no computers involved. The method was patient, physical and entirely reproducible, which is part of why the report still carries weight.

The Numbers: 2,457 mph and 1,479 g

Any speed derived from a film depends entirely on how far away the objects were, and nobody knew. The Navy handled this by choosing a distance it could defend: five miles. Its reasoning was that at five miles, an object 50 feet across would show resolvable detail on the film, and none of these objects did.

On that assumption the analysts produced the figures the report is now known for.

For scale: a fighter pilot in a modern jet blacks out somewhere around 9 g. Airframes are built to survive an order of magnitude more than that, not two. Nothing flying in 1953 could produce 1,479 g, and nothing flying now can either. That is precisely why the distance assumption matters — halve the range and every figure falls with it. The Navy knew this, which is why it stated its assumption plainly rather than burying it.

What the Navy Actually Concluded

The report answers a set of numbered questions put to it by the Air Force. The first answer is the one that matters.

The second answer is blunter still.

The team also tested the obvious alternative directly. If these were reflective spheroids — balloons catching sunlight — they should blink as they rotated through a 60-degree arc over 90 seconds at 16 frames per second. They do not. And, the report adds, "the velocity and acceleration computations rule this possibility out."

Then the analysts did something careful: they took the data outside their own building. Cleared experts in astronomy and physics were shown the preliminary findings. They offered natural-phenomena theories, but according to the report they "were not able to do so under the conditions during which the photography was taken, nor were they able to recognize these objects as man-made."

How the Objects Behaved on Film

Beyond the headline numbers, the report contains a frame-by-frame description of the objects' behaviour that is rarely quoted.

That last line is the most tantalising in the document. A quantised pattern in a set of measurements usually points at something in the method — a rounding step, a frame-rate artefact, a limit of the projection rig. It might mean nothing at all. But the analysts saw it, thought it worth recording, and then ran out of equipment, money and personnel before anyone could chase it. As far as the public record shows, nobody ever has.

The Seagull Problem: This Report Versus the Robertson Panel

Here is the context that makes the document historically interesting rather than merely thorough.

In January 1953 the CIA convened a panel of scientists chaired by physicist H. P. Robertson to review the UFO problem. The panel looked at the Tremonton film among other material and concluded the objects were birds — seagulls, catching the sun. That verdict shaped official US policy on UFO reports for years afterwards and is still the standard sceptical explanation for the film today.

This Navy report is dated 4 May 1953, months after the panel reported, and says birds are ruled out. It does not mention the panel at all, so we should be careful how we characterise it: this is not the Navy publicly contradicting the CIA. It is a technical unit completing the job it was given and putting its own finding on the record, apparently unmoved by the conclusion that had already been reached elsewhere.

Which of the two was right is still open. Seagulls do soar in loose groups, they do catch the light, and a bird at close range can be mistaken for a large object far away — the entire argument turns on the distance assumption. What the released report shows is that the people best qualified to read the film, and the only ones who measured it frame by frame, did not agree with the seagull verdict.

Timeline

What It Adds Up To

This report does not prove anything flew over Utah that could not have been made on Earth. Its central number rests on an assumption about distance that cannot be verified, and its authors say so. Read it as a measurement exercise with a stated premise, and it is honest work.

What it does establish is narrower and more durable. In 1953, a unit of professional image analysts spent months on two films, measured them properly, consulted cleared scientists, tested the balloon hypothesis and rejected it, wrote down that birds and aircraft were ruled out, and sent that conclusion to the Director of Naval Intelligence. Then the file was classified for seventy-three years, while the public account of the same film settled on seagulls.

That gap between what was concluded internally and what was said publicly is the recurring theme of the whole 2026 release programme. We found the same pattern in the 1947–48 Air Force correspondence covered in the Project SIGN file, and in the wider batch these documents came from, covered in our breakdown of the fifth UFO file release.

Read the Report Yourself

The full 23-page report is public domain and free to download from war.gov/ufo as DOW-UAP-D098. Pages 1 to 9 carry the written analysis; the rest are the hand-plotted charts. Both films themselves have been in the public domain for decades. Our catalogue of the primary sources is in the UAP document archive.

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