A bit off topic theory but in continuity with this "native" approach.
What about a herd of reindeers? The area is still populated by the last remaining wild herds : https://www.ipae.uran.ru/sites/default/files/publications/
The antler on pole could signal the entry of a very special hunting zone (or on the contrary the zone where the herd cannot be hunted), where a "mythical" wild herd roams.
Things happen like this:
+ Herd (200 or so animals) is hunted (by men or animals, or just on the move) from an opposite side (from where the group came or where it is going) of ridge and crosses it running, tramps the tent (do reindeers do that if not frightened? maybe they didn't see it since it was half sunken in snow), leaving it in chaos and with some people with heavy injuries (head, ribs)
+ since the tent is ruined, group decides to go to the tree line (maybe it's morning and they can see the trees very well, wind has calmed and clouds are away) to find shelter
+ they make a "den" for the injured and leave them there. The 5 other start a fire that will be a landmark to come back to, 3 go back to the tent but run low on adrenaline and cannot make it. the 2 at the fire are worried about the wounded and give them their clothes (they think the fire is enough to keep warm, but it isn't and even stops: they die believing the 3 are on their way back)
+ no explanation for radioactivity (even if i like the isotope tracking of sensible personnel by kgs a good one), or "mutilations"
+ why footprints and no sign of the passage of the herd? because the herd was going along the slope towards (or from) the pass where snow was hard: reindeers would not run in a direction with "ravines"
so, no murderers, no military, no ufo, no lightning ball, no lying Mansi ... just a natural (reindeers) compelling force