KRIVONISCHENKO'S CAMERA / ARSH RAZIUDDIN / THE ATLANTIC

Precisely 61 years ago, a band of skiers trekking through the Ural Mountains stashed food, extra skis, and a well-worn mandolin in a valley to pick up on the way back from their expedition. In a moment of lightheartedness, one drew up a fake newspaper with headlines about their trip: “According to the latest information, abominable snowmen live in the northern Urals.” Their excess equipment stored away, the group began moving toward the slope of Peak 1079, known among the region’s indigenous people as “Dead Mountain.” A photograph showed the lead skiers disappearing into sheets of whipping snow as the weather worsened.

Later that night, the nine experienced trekkers burst out of their tent half-dressed and fled to their deaths in a blizzard. Some of their corpses were found with broken bones; one was missing her tongue. For decades, few people beyond the group’s friends and family were aware of the event. It only became known to the wider public in 1990, when a retired official’s account ignited a curiosity that soon metastasized.

Today, the “Dyatlov Pass incident,” named after one of the students on the trek, Igor Dyatlov, has become Russia's biggest unsolved mystery, a font of endless conspiracy theories. Aliens, government agents, “Arctic dwarves”—and yes, even abominable snowmen—have at various points been blamed for the deaths. One state-television show regularly puts self-appointed experts through a theatrical lie-detector test to check their outlandish explanations.

A year ago, the Russian prosecutor general's office announced a new inquiry into the deaths, to stop what it called the “growth of rumors” and to “establish the truth.” Investigators traveled to the area to reenact parts of the incident and are expected to announce their conclusions soon.

But if the Dyatlov Pass incident has shown anything, it's that closure will be elusive. Even a definitive judgment is unlikely to quell speculation: In Russia, conspiracy theories are an essential part of daily life.

“It's our Soviet mystery that we want to solve,” Natalya Barsegova, who has been publishing articles on the case for the newspaper Komsomolskaya Pravda since 2012, told me. “Every person who starts researching it thinks he's the one who can solve it, but the deeper he goes, the more the swamp sucks him in.”

An unsolved mystery such as the Dyatlov Pass incident would no doubt rile up truthers in the United States, but the Russian obsession with the incident is above and beyond American internet-forum debates on Area 51 and the chupacabra. Whereas U.S. conspiracy theories often develop on the fringes of public life—a line that has admittedly been blurred in the Donald Trump era—conspiracy-mongering is mainstream in Russia, a country in which 57 percent of the population believes the Apollo moon landings were a hoax.

And while this belief in secret plots typically begins at the grassroots level in the U.S., in Russia it has more often come from the top down. In the late 1800s, the tsarist state began encouraging conspiracy theories targeting Jews and Catholics as a way to rally Russians against the West. The Protocols of the Elders of Zion, a fake document cited as evidence of Jewish plans for global domination by Adolf Hitler, was first published in Russia in 1903 at the height of the pogroms.

In the Soviet era, officials regularly found conspiracies of capitalist spies and counter-revolutionaries, killing and imprisoning millions for such imagined offenses during Stalin's Great Terror. Manufactured suspicions were directed outward as well: When Moscow accidentally shot down Korean Air Lines Flight 007 in 1983, it claimed that the plane was part of a U.S. plot to start a war. The denunciations of neighbors and widespread state surveillance, the cover-ups and deceit, led to paranoia among the citizenry. People had to read between the lines of party mouthpieces to get any sense of what was really going on. As a result, the columnist Oleg Kashin has argued, many still feel today that something “was hidden behind the black-and-white photographs” of the Dyatlov expedition.

That habit of piecing together one’s own explanation has persisted after the collapse of the Soviet Union, compounded by a deep-rooted cynicism and the Kremlin’s own propaganda. The government of Vladimir Putin—who once claimed that the internet was a “CIA project”—routinely suggests that Western plots are behind everything from Russia’s Olympic doping ban to Syria’s White Helmet volunteers. Online troll farms, pro-Kremlin pundits, and sensationalist state news outlets like Sputnik and RT pitch in too: One state-television host’s insinuating catchphrase—“Coincidence? I don’t think so”—has become an internet meme.

Obfuscation is the default reaction to any accusation. When Malaysian Airlines Flight 17 was blown apart over eastern Ukraine by a Russian missile in 2014, the defense ministry in Moscow argued that it could have been shot down in a false-flag operation. When the poisoning of Sergei Skripal was tied to Russian agents, the foreign ministry hinted that a British laboratory was the real culprit. Most recently, parliamentarians have claimed that last summer’s protests in Moscow were orchestrated by Washington. Truth is seen as relative, and conspiracy has become the coin of the realm.

Here’s what we know about the Dyatlov Pass incident: The nine skiers, all college students, had set out from Yekaterinburg, then known by its communist name, Sverdlovsk, in January 1959, singing songs on an overnight train. They planned to ski about 200 miles over 16 days, summiting several peaks along the way, allowing enough time to be back for the spring semester. After catching a lift with some lumberjacks and following a sleigh driver north, the group skied out of an abandoned village on January 28, eventually making it to their final campsite on February 1.

Searchers later found their tracks along a frozen river, and, upon reaching Dead Mountain, stumbled across a half-collapsed tent on a steep, windswept slope. Inside, food supplies and outer clothing were laid out, as if the group had been about to cook dinner. Nine pairs of boots stood along one wall. Bizarrely, the tent appeared to have been slashed open—from within.

In the forest below, the investigators came across two bodies under a cedar tree, lying next to the remains of a fire. Although the temperature had been down to -40 degrees Fahrenheit the night the group disappeared, the pair were wearing only long underwear. Fragments of human skin on the tree revealed that they had broken off branches. The bodies of Dyatlov and two others, also without shoes and coats, were found several hundred feet away. It wasn't until the snow began to thaw two months later that the remaining four corpses were found. Two had broken ribs, and one's skull was partially crushed.

The inquiry, carried out in spring 1959, left many questions unresolved. Why did the skiers flee the tent to certain death in the wind and snow? What caused the blunt-force traumas? Why did an analysis find elevated levels of radioactivity on two of the victims' clothing? These questions were all beyond the purview of the official investigators, who, while baffled, concluded that there had been no foul play, and that the students were killed by an “elemental force that the tourists were not able to overcome.” The case was closed, and the findings were archived as “secret,” as was routine in the Soviet Union at the time.

A local journalist was barred from filing a report on the incident, and for decades the only publication related to the mystery was a novel by one of the searchers. (It had a slightly happier ending: After hurricane-force winds blow one girl down the slope and trap the others who rush to help her, the group leader attempts to return to the tent and dies. The rest find shelter in a trapper's hut.) But then came the Soviet breakup, which lifted the curtain of silence over the traumatic past. The extent of Stalin's repressions was revealed to the public, as was the existence of the Molotov-Ribbentrop Pact. Impoverished by financial collapse, and shocked that much of what they had been taught since childhood was a lie, many Russians were cast emotionally adrift. Faith healing, cults, and pyramid schemes flourished.

Onto this ripe ground fell the seed of the Dyatlov mystery. In January 1990, the former Communist Party head of a town near the Dyatlov Pass wrote a response to a newspaper article about a supposed UFO sighting in the area. In it, he described what had happened to the skiers, claiming that holes in their tent were made by falling debris from a rocket test. The paper later published a story in which Lev Ivanov, the lead investigator on the 1959 Dyatlov inquiry, was quoted as saying the students were killed by a UFO. The article also repeated rumors that the group could have been killed by indigenous people or radiation from a weapons test. (In fact, the “balls of fire” referred to in the story had been seen weeks after the students’ deaths and were attributable to documented missile tests.) A few months later, Ivanov wrote his own article in another newspaper blaming the students' injuries on a “heat ray or a strong energy that is completely unknown to us.” With UFOs, secret documents, and hints of a government cover-up—“Khrushchev was informed about the event at the very beginning,” Ivanov wrote—the articles were a conspiracy-theory starter kit. By the late 2000s, “Dyatlophrenia” had made it to national newspapers and television.

An ever-growing web of theories has since emerged, claiming that poisoned alcohol, the descendants of ancient “Aryans,” or a variety of fantastical weapons like a “vacuum bomb” were responsible. The fact that the deputy engineer of the Chernobyl nuclear power plant had the same surname as Igor Dyatlov raised suspicions of some connection to that disaster. Several theories hold that the Dyatlov group included a KGB or CIA agent.

Even those closest to the tragedy have blamed the deaths on some nefarious plot. Yuri Yudin, a student who briefly accompanied the group before turning back due to illness, said before his death that he believed his friends “saw something they shouldn't have seen” and were forced at gunpoint to fabricate a scene to confuse investigators, then left to die.

When I spoke to Yuri Kuntsevich, who attended the students' funerals as a boy and has since become an oft-quoted researcher and head of the Dyatlov Memorial Fund, I was hoping for a clear-eyed assessment to cut through the noise. Instead, he argued that the students had been asked by a Western agent named “the Mole” to photograph a secret missile test. After doing so, they were murdered by drunken convicts guarding the pass. “Then they moved the tent 1.5 kilometers to an impractical place. That was done by a mop-up team [of soldiers]; they had several helicopters,” he told me matter-of-factly.

Dyatlov’s own sister, Tatyana Perminova, told me she had heard a raft of theories, but could only repeat what her parents had told her at the time of her brother’s disappearance and death. “They were sure,” she said, “that the military was somehow involved.”

So what really did happen the night of February 1, 1959? The theory put forward by the American researcher Donnie Eichar, as well as by some Russian scientists, is that severe winds blowing over the dome of the mountain created a “Kármán vortex street” of whirlwinds, which produced a low-frequency sound that is not entirely audible but vibrates hair cells in the ear, causing nausea and intense psychological discomfort. Under that onslaught in the pitch dark, the students could have been overcome by feelings of fear and panic.

When announcing its inquiry last year, the Russian prosecutor general ruled out “criminal” explanations and said it was focusing on three natural causes—an avalanche, a snow slab, or a hurricane. That has done little to keep the rumor machine from kicking into high gear. For months, fantastic new theories emerged on websites and TV shows, while Kuntsevich and relatives of some of the Dyatlov group, angry at prosecutors’ refusal to consider non-natural causes for the deaths, have filed a complaint asking investigators to open a criminal case.

That’s the difficulty with conspiracy theories in Russia and elsewhere: Even if the real explanation is found, not everyone will believe it. The mystery of the Dyatlov Pass incident may one day be solved, but it will never truly be put to rest.

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