The Dyatlov Pass incident refers to an event that resulted in the deaths of nine ski hikers in the northern Ural mountains on the night of February 2, 1959. It happened on the east shoulder of the mountain Kholat Syakhl (Холат Сяхл) (a Mansi name, meaning Mountain of the Dead). The mountain pass where the incident occurred has since been named Dyatlov Pass (Перевал Дятлова) after the group’s leader, Igor Dyatlov (Игорь Дятлов). The lack of eyewitnesses has inspired much speculation. Soviet investigators determined only that “a compelling unknown force” had caused the deaths.
After half a century, the mystery remains. What was the nature of the deadly “unknown force”?
A number of solutions have been put forward, involving everything from hostile tribes and abominable snowmen to aliens and secret military technology.
Note: One thing not mentioned in this video is that a note was found near the campsite that said “from now on we know there are snowmen”
A useful link with detailed information about the Dyatlov Pass Incident, Here