Within Great Falls
Why Great Falls' Skies Can Mislead Witnesses
Long sightlines around Great Falls make strange objects easier to notice but much harder to judge for distance, size and speed.
On this page
- How distance and speed become difficult to judge
- Why hovering, shape changes and formations can be illusions
- What better instruments would need to measure
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Introduction
Great Falls is often described as one of Montana’s most important UFO locations, but one of the least appreciated reasons is also one of the simplest: the sky itself. The city sits beneath broad plains and open horizons where objects can remain visible for long periods with very few landmarks to provide scale. That makes unusual lights, aircraft and distant objects easier to notice than in heavily forested or urban environments. It also makes them harder to judge accurately.
This matters because many of the characteristics people associate with UFOs—extreme speed, sudden hovering, shape changes and unusual formations—can emerge when observers lack reliable information about distance, altitude and direction. In Great Falls, long sightlines increase the chance of seeing something unusual, while simultaneously reducing the visual cues needed to identify it confidently. The result is a setting that can generate genuine mysteries, but also one that naturally amplifies perception problems that investigators have recognised for decades.[Wikipedia]WikipediaMariana UFO filmMariana UFO film
How Distance and Speed Become Difficult to Judge
The most important limitation in an open-sky environment is the loss of scale. Human vision is surprisingly poor at estimating the size or distance of an object seen against a mostly featureless background.
In Great Falls, an observer looking toward the horizon may see an object dozens of miles away with no nearby buildings, trees or terrain features to provide reference points. A small nearby object and a large distant object can occupy nearly the same apparent size in the sky. Once distance becomes uncertain, estimates of speed become uncertain as well.
This is particularly relevant to reports of fast-moving UFOs. A distant aircraft crossing a large section of the sky can appear extraordinarily fast because the observer assumes it is closer than it really is. Conversely, a nearby object can seem surprisingly slow if it is assumed to be much farther away. Investigators of aerial phenomena routinely note that range estimation is one of the weakest parts of eyewitness testimony because the human eye alone provides little reliable distance information in open airspace.[Skybrary]skybrary.aeroVisual Illusions AwarenessVisual illusions may result in landing short of the runway, hard landing or runway overrun, but may als…
Great Falls’ geography intensifies this problem. The surrounding plains offer exceptionally long sightlines, allowing observers to track objects for longer periods than would be possible in more obstructed landscapes. A longer observation can increase confidence in what was seen, yet confidence is not the same as accuracy. A witness may watch an object for several minutes while still lacking the information needed to determine its true altitude, size or speed.
The famous 1950 Mariana film illustrates the difficulty. Nick Mariana reported seeing two bright, silvery objects moving across the sky over Great Falls. The film remains historically significant, but later analyses noted that the footage itself contained too little information to determine the objects’ actual distance, trajectory or physical dimensions with certainty. Investigators could study the images, but the absence of reliable range data limited what could be concluded from the film alone.[Wikipedia]WikipediaMariana UFO filmMariana UFO film
Why Hovering, Shape Changes and Formations Can Be Illusions
Some of the most striking UFO descriptions can emerge from ordinary visual geometry.
The Illusion of Hovering
One common example occurs when an aircraft approaches an observer nearly head-on. Because most of its movement is toward the viewer rather than across the field of vision, it can appear almost stationary.
To someone on the ground, especially under a vast open sky, the object may seem to hover for an extended period before suddenly moving away or changing direction. In reality, the aircraft may have been travelling at normal speed the entire time. Aviation specialists have long recognised similar visual illusions in flight operations, where perception can diverge significantly from actual motion.[Skybrary]skybrary.aeroVisual Illusions AwarenessVisual illusions may result in landing short of the runway, hard landing or runway overrun, but may als…
Apparent Shape Changes
Bright objects can also appear to change shape. Atmospheric haze, heat distortion, changing viewing angles and fluctuations in reflected sunlight may alter an object’s appearance over time.
An aircraft reflecting sunlight may appear circular at one moment, elongated at another and irregular a few seconds later. Against a clear blue Montana sky, such changes can be dramatic because the object may be visible continuously while lighting conditions shift. Witnesses sometimes interpret these changes as evidence of rotation or transformation, even when the effect originates from changing geometry between the observer, the object and the Sun.[Skybrary]skybrary.aeroVisual Illusions AwarenessVisual illusions may result in landing short of the runway, hard landing or runway overrun, but may als…
Formation Effects
Open skies can also create misleading impressions of coordinated movement.
Objects separated by large distances may appear close together when viewed along a similar line of sight. Two aircraft travelling independently can seem to maintain a fixed formation. Likewise, an observer may perceive one object following another when they are actually operating at different altitudes and ranges.
This is particularly relevant in a region with significant civilian and military aviation activity. Without depth cues, separate objects can appear linked in ways that later prove difficult to verify.[Skybrary]skybrary.aeroVisual Illusions AwarenessVisual illusions may result in landing short of the runway, hard landing or runway overrun, but may als…
Why Great Falls Produces Long-Lasting Sightings
Many UFO reports are brief. Great Falls often produces sightings that last longer.
At first glance, a lengthy observation seems like stronger evidence. Yet prolonged visibility can sometimes increase the opportunity for misinterpretation. An object visible for several minutes allows the observer to notice apparent manoeuvres, brightness changes and positional shifts that may actually result from perspective effects.
The open terrain around Great Falls permits people to follow distant aircraft, balloons and lights over much larger sections of sky than observers in mountainous valleys or built-up cities. A witness may therefore accumulate a detailed narrative about an object’s behaviour while still lacking accurate information about its distance and altitude.
This helps explain why Great Falls occupies an important place in Montana’s UFO history. The region does not merely generate reports because people are interested in the subject. Its geography creates ideal conditions for observing aerial objects, but not necessarily for identifying them. That combination naturally produces more reports that remain debated long after the event.[wikipedia.org]WikipediaMariana UFO filmMariana UFO film
What Better Instruments Would Need to Measure
The limitations of eyewitness observation are one reason modern UAP researchers increasingly emphasise instruments rather than testimony alone.
To determine whether an unusual object is genuinely anomalous, investigators ideally need multiple independent measurements of the same target. Important data include:
- Distance and altitude, obtained through triangulation from more than one observation point.
- True speed, calculated from known positions rather than visual estimates.
- Radar information, which can independently confirm location and movement.
- Optical measurements, including high-resolution imagery and precise timing.
- Spectral data, which can reveal how an object emits or reflects light.
Modern scientific proposals for UAP investigation stress multi-sensor observations because a single camera or eyewitness rarely provides enough information to distinguish between an unusual object and a perceptual illusion. When range is known, many apparent mysteries become easier to evaluate. When range remains unknown, even clear-looking observations can remain ambiguous.[caltech.edu]authors.library.caltech.eduWe describe an approach for highlighting outlier events…
Why This Matters for Great Falls’ UFO History
Great Falls’ reputation as a UFO hotspot is tied not only to famous incidents but also to the environment in which those incidents occurred. The city’s expansive skies offer extraordinary visibility, allowing residents to notice distant objects that might pass unseen elsewhere. Yet the same openness removes many of the visual cues people rely on to judge size, distance and motion.
That does not mean every sighting has a simple explanation. Some reports remain unresolved because the available evidence is incomplete. However, understanding the visual challenges created by Great Falls’ landscape helps explain why the region repeatedly generates reports of hovering objects, dramatic speed estimates, changing shapes and unusual formations.
In Montana’s UFO history, the open sky is therefore not just a backdrop. It is part of the mechanism that shapes what witnesses see—and what investigators later struggle to prove.[wikipedia.org]WikipediaMariana UFO filmMariana UFO film
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Endnotes
1.
Source: Wikipedia
Title: Mariana UFO film
Link:https://en.wikipedia.org/wiki/Mariana_UFO_film
2.
Source: skybrary.aero
Link:https://skybrary.aero/sites/default/files/bookshelf/177.pdf
Source snippet
Visual Illusions AwarenessVisual illusions may result in landing short of the runway, hard landing or runway overrun, but may als...
3.
Source: arxiv.org
Link:https://arxiv.org/html/2411.02401v1
Source snippet
A Civilian Astronomer's Guide to UAP Research5 Nov 2024 — This review explores how astronomers can enhance our understanding of thes...
4.
Source: arxiv.org
Title: arXiv The New Science of Unidentified Aerospace-Undersea Phenomena (UAP)
Link:https://arxiv.org/abs/2502.06794
5.
Source: arxiv.org
Title: Unidentified Aerial Phenomena
Link:https://arxiv.org/html/2503.05627v1
Source snippet
Characterization of Dark...13 Feb 2025 — We use high-tech observations of Unidentified Aerial Phenomena (UAP) class objects to evaluate...
6.
Source: arxiv.org
Link:https://arxiv.org/pdf/2211.17085
7.
Source: arxiv.org
Link:https://arxiv.org/abs/2211.17085
8.
Source: authors.library.caltech.edu
Link:https://authors.library.caltech.edu/records/rcjwj-zr809
Source snippet
We describe an approach for highlighting outlier events...
9.
Source: greatfallshistorymuseum.org
Link:https://www.greatfallshistorymuseum.org/blog/the-mariana-ufo-great-falls-visiting-voyagers
Source snippet
The History MuseumMariana UFO Incident: Great Falls' Visiting Voyagers1 Sept 2025 — Great Falls has had over 100 reported UFO sightings...
10.
Source: ui.adsabs.harvard.edu
Link:https://ui.adsabs.harvard.edu/abs/arXiv%3A2208.11215
Additional References
11.
Source: krtv.com
Title: great falls ufo legacy in focus amid pentagon document release
Link:https://www.krtv.com/news/great-falls-news/great-falls-ufo-legacy-in-focus-amid-pentagon-document-release
Source snippet
UFO sightings - and it happened right here in Great Falls.... Whether Mariana saw UFOs or not, the sighting became famous for its video...
12.
Source: calaero.edu
Title: 7 runway illusions
Link:https://calaero.edu/learn-to-fly/aeronautics/aeromedical-factors/7-runway-illusions/
Source snippet
CAU7 Runway Illusions Every Pilot Should Understand and...11 Jul 2023 — When your runway or the surrounding terrain has a downslope to t...
13.
Source: youtube.com
Title: Meet the Author: “No Cause for Alarm: Flying Saucer Mania and the Montana Movie”
Link:https://www.youtube.com/watch?v=g9z6mFM3iSo
Source snippet
UFO Over Montana: The Mariana Incident & The Great Falls Mystery...
14.
Source: youtube.com
Title: Spatial Disorientation Explained: Deadly Flight Illusions Every Pilot Must Know
Link:https://www.youtube.com/watch?v=6BD9fyyIJzY
Source snippet
Why Sun looks flat at dawn or dusk? Atmospheric Refraction...
15.
Source: youtube.com
Title: UFO Over Montana: The Mariana Incident & The Great Falls Mystery
Link:https://www.youtube.com/watch?v=MBPYf7wT40w
Source snippet
Spatial Disorientation Explained: Deadly Flight Illusions Every Pilot Must Know...
16.
Source: youtube.com
Title: The Montana Film: The First Recorded UFO Sighting in the US
Link:https://www.youtube.com/watch?v=DJ2vKHj8rVM
Source snippet
Meet the Author: "No Cause for Alarm: Flying Saucer Mania and the Montana Movie"...
17.
Source: ulc.gov.pl
Link:https://ulc.gov.pl/download/bezpieczenstow_lotow/ALAR/BN_5.3-_Visual_Illusions.pdf
18.
Source: facebook.com
Link:https://www.facebook.com/iskysthelimit/posts/human-factors-optical-illusionssafersmarter-more-confident-pilotsbecousesmartpil/722325211571593/?locale=ms_MY
19.
Source: instagram.com
Link:https://www.instagram.com/p/DWYRMg7FDxS/
20.
Source: facebook.com
Link:https://www.facebook.com/mary.kate.teske.2025/posts/the-first-documented-motion-picture-footage-of-a-ufo-was-captured-by-nick-marian/1039363715177073/