Photo from Russian governmental investigation.

Chilled by Siberian air masses that accumulate during winter, the steel-colored eastern shoulder of Kholat Syakhl (“Dead Mountain” in local tribal language) in Russia’s northern Ural mountains seems like the kind of place an unexplained mystery would take place. And it was. In February 1959, nine ski hikers wandered off-route through this pass and were never seen alive again. The bizarre details surrounding their deaths have inspired a bounty of theories that deviate from the official investigation’s report, which claimed that “a compelling natural force” caused their deaths.

Igor Dyatlov led an expedition of eight fellow students and graduates of Ural Polytechnical Institute, all well-versed in the rhythms of long ski tours and high mountain trekking. On their way to the peak of Otorten after stocking their surplus food and equipment for the trip back in a wooded valley, they began to move through what is now called the Dyatlov Pass. But the glittering fog of a worsening snowstorm compromised their visibility and the team was thrown off course, closer to Dead Mountain. Realizing their mistake, they set up camp on its cold slope.

Sometime that night, a tent with five of the hikers was ripped open with a knife from the inside, and its occupants fled barefoot out of it clad only in underwear — into the snow-packed dark. Their bodies were found a mile northeast at the edge of a nearby forest near the remains of a fire, forming a line in positions suggesting they were trying to return to their tent when they died.

The other four were found deeper in the forest, at the base of a cedar tree. Three of the bodies showed no outward signs of injury, but further tests revealed massive internal injuries on par with a “high level of pressure”, like that of a car crash. The last hiker, however, was unrecognizable — her face missing eyes and tongue, its skin and hands heavily macerated. Later, forensic tests of these hikers’ clothing were found to be radioactive.

A medical examiner ruled that they had all died of hypothermia and the final verdict put “a compelling natural force” at fault. The case was closed and sent to a secret archive only to open again in the 90s (with some files missing). It was then that many investigators involved with the case came forward with new facts, including Lev Ivanov who led the official inquest in 1959, and said he was ordered to dismiss the case by high-ranking officials after his team reported seeing flying spheres in the vicinity of the incident.

Many theories have been speculated in the mysterious deaths of the nine ski hikers who perished on Dyatlov Pass – paranormal activity, secret weapons test, murder at the hands of a local mountain tribe – but none have been proven. To this day, their story remains the stuff of legend, the sole survivor of which is Dead Mountain itself.