Dyatlov Pass



Dyatlov Pass is a mountain pass near Kholat Syakhl in the northern Urals in Russia, which entered the annals of conspiracy theory, cryptozoology, and ufology in 1959. Nine ski hikers mysteriously died there in one night, apparently running out of their tents into the snow semi-dressed, and perishing there &mdash; mostly of hypothermia but some with signs of trauma from something of more than human strength.

What we know
The dead were all from the Ural Polytechnical Institute in Yekaterinburg, one of the largest technical institutes in Russia. There were eight men and two women in the party, including leader Igor Dyatlov (after whom the pass was subsequently named). All had previously experienced similar expeditions by ski through tough Russian winters. Their plan was a 350 km journey by ski to the peak of Otorten, 10 km from the pass. Otorten's name in the local Mansi language means "Don't go there". The party began their trek at Vizhai on 27 January 1959; the following day one member, Yuri Yudin, turned back, leaving 9 to continue.

From journals and photographs, it appears that they reached the edge of the mountains on 31 January. The following day, they set off to cross the pass, but seem to have taken a wrong direction and found themselves higher than expected on the side of Kholat Syakhi. They decided to camp for the night on the slopes, rather than descending. The weather then was particularly cold, falling to -24° C. That night, something happened.

Investigations
After they failed to return, their tent was discovered by a search party on 26 February; rescuers found it apparently cut open from the inside (some sources say torn open). There are claims that the tent was erected incorrectly, which was surprising with such experienced trekkers (was it moved, or did they just put it up in a hurry?). The bodies of all 9 were discovered in the following months. Those nearest the tent were semi-naked and some were barefoot; evidently they had not had time to dress. (It should be noted that hypothermia can cause so-called "paradoxical undressing", where victims feel unusually warm and disrobe despite the extreme cold.) The last four were better clad, some in the clothes of their comrades, buried under snow in a ravine further down the slope. One of them, Semyon Zolotariov, had a camera around his neck, although the film was damaged.

Autopsies on the first five bodies found they had died of hypothermia, even though one (Rustem Slobodin) had a minor crack in his skull. But the bodies of the last four showed serious injuries: chest fractures and skull fractures consistent with crushing injuries but no signs of external trauma to most. It was judged that three had died as the result of extreme trauma by something stronger than a human being. One, Lyudmila Dubinina, had facial wounds including missing tongue and eyes (which could have been caused by decomposition or subsequent predation, rather than by her attacker, though the large amount of blood in her stomach suggests her tongue may have been removed while she was alive or soon after her death). Some reports suggest strange discolouration of their hair and eyes, but they had been dead and decomposing for months by the time they were found.

The group had left diaries and photographs, which provided useful evidence of the early course of the trek, but little clue as to what had happened that night. The last photograph they took showed only an unidentifiable blurry shape. The initial government investigation failed to find an explanation, blaming an unknown force for the killings. It is believed that all government files relating to the issue have been released, starting in the late 1980s.

Theories
(Roughly in order from most plausible to most fanciful)

Avalanche
One of the more mundane theories holds that they panicked with the thought that an avalanche was imminent, and ran out to avoid being buried. There was no evidence of an avalanche nearby at the time, and it's not a particularly avalanche-prone area, and they were experienced with mountains and snow, although none of that proves they didn't panic incorrectly.

The avalanche theory has gained in popularity recently. A 2019 Russian government inquiry concluded it was the most likely cause, which may not convince many skeptics. Johan Gaume, an avalanche researcher in Switzerland, conducted research using computer models of snow and data on the impact of automobile crashes on human bodies to suggest a small avalanche involving a heavy slab of compacted snow could have been responsible. Winds moving snow during the fateful night and the consequences of pitching their tent in an indentation on the uneven landscape put them in a particularly unlucky place.

Local tribespeople
An early theory was that they were murdered by the indigenous However, there was no evidence of their presence (such as tracks in the snow), and the nature of the students' wounds made such an attack unlikely, so the theory was rejected by investigators.

Animal attack
Were they killed by bears? This doesn't fit with the lack of tracks, or explain why they left their tent.

High winds
Winds could have blown one or more people away, leading to the rest leaving to mount a search. Against this, the tent was still in place without any sign of severe wind.

Some kind of argument
Could they have quarrelled, leading some to storm out? Against this, the party all knew each other and had travelled together before, they were sensible and experienced trekkers, and there were no signs of drugs or drinking.

Nearby gulag
There was allegedly a Soviet prison nearby, which leads to theories that they were killed by escaped prisoners, or killed by guards who mistook them for escaped prisoners, or killed to cover up something else. Again, this doesn't really fit with what investigators found or the wounds sustained, but it's hard to prove definitively either way.

Secret weapons experiment
Anatoly Gushchin in The Price of State Secrets Is Nine Lives claimed the investigating team had seen flying spheres and Gushchin blamed the incident on a secret Soviet weapons test.

There was, it is claimed, a high level of radioactive contamination around the bodies. On the other hand, radioactive thorium was used for wicks (mantles) in lamps. And the reports aren't terribly clear or consistent on exactly where the radiation was; it could have come from another source nearby.

There were also suggestions that the Soviets had been testing parachute mines in the area, weapons which descend slowly from the sky and explode just above the ground. This could explain the students' injuries. Or it has also been claimed that they were killed by the government to prevent them spilling secrets about weapons tests. However, it seems an odd way to kill people.

Infrasound
American filmmaker Donnie Eichar in Dead Mountain: The Untold True Story of the Dyatlov Pass Incident blamed infrasound, a naturally occurring phenomenon where wind striking mountains can produce a low frequency hum. It can induce "powerful feelings of nausea, panic, dread, chills, nervousness, raised heartbeat rate and breathing difficulties". Eichar suggests that the trekkers were disturbed by infrasound, panicked, and ran out into the snow. Perhaps the hikers had heard tales of the zolotaya baba (see below) and thought they were being stalked by one upon hearing strange sounds and getting a creepy feeling from the infrasound? This doesn't explain some of their injuries, however, such as the burns on some of the victims' bodies.

Yeti
Could they have been killed by some sort of cryptid, a yeti or ape-man unknown to science? Locals supposedly fear the zolotaya baba ("golden woman").

In 2014 the Discovery Channel (a cable channel known for its ridiculous, ill-informed programming) aired Russian Yeti: The Killer Lives. The "documentary" claimed the trekkers had seen and photographed the cryptid, leaving a note saying "We now know snowmen exist" &mdash; but no other mention in their diaries. Furthermore, no tracks other than the hikers were found, casting more doubt on this theory.

UFO
Reportedly, government investigator Lev Ivanov privately blamed UFOs. Of course, aliens could have done almost anything. Why'd they kill a group of hikers in a remote part of the world is a question which they probably won't answer any time soon.

There are reports of strange lights being seen around the mountain around the time of their death, and while they haven't been identified, that doesn't automatically mean aliens. It could have been anything else and may not even be linked to their deaths.

Fictional treatments
The incident was popularised by Anna Matveyeva's novella The Mystery of Dyatlov Pass (2000), which mixes documentary evidence with the imagined experiences of a woman in the party, and is hence widely used as a source of factual information.

Finnish director Renny Harlin, who had earlier shown a talent for mountain films with the Sylvester Stallone vehicle Cliffhanger, made a fiction film Dyatlov Pass Incident (a.k.a., Devil's Pass), released in 2013 in Russia.

Similar cases
Although not directly comparable, it bears some resemblance to the mysterious disappearance of lighthouse keepers from Flannan Isle in 1900, and the disappearance of the crew of the Mary Celeste.

An incident referred to as "America's Dyatlov Pass" where five friends from Yuba City, all mentally disabled, disappeared for months, with four of the bodies found in the aftermath, is also worth mentioning and similarly remains unsolved.