I think if it was the Mansi that made the fire the searchers would have found bigger logs, wood shavings from Saws or axes .
Plus the chum thing that we have the photo of is possibly a wood store and a sign post . I did read ages ago that the Mansi stored wood like this to dry . The chum location seems to be just north of where Zina was found .
Tha advantage of the snow when searching is that it leaves a trail to activities at that moment in time. It is the thaw in May that's shows this level of twigs and debris being dragged to the ravine along with items of clothing. No other traces are recorded, no tin cans, no bones of animals , no other attempts to cut trees , just the 14 or so branches that were used for the den flooring and the broken branches off the Cedar.
It is reported by another that there was considerable melted snow ( gone hard I think) around the fire and that the Yuri's were lying on fir branches . It would be logical to assume this was for insulation from the snow.
As hunter says , they did not have serious tools to process the wood and climbing a tree to get the weathered branches makes some sense for the hikers but not for Mansi or any outsider's, they would have tools and build a big fire. From building this fire , there would be signs in the snow that this happened. There is nothing there but the broken cedar branches which are burnt through, some branches lying on the lower branches of the cedar that didn't reach the ground and some used as flooring at the cedar.
It is this that confuses me as to why they didn't drag those branches to the den for more insulation and make the fire next to the den.
Given the state of the two Yuri's, their burns , the socks lying around and removal of the lower clothing I can't but help think they got wet which is a small possibility as the ravine comes before the cedar .
For me the activity at the cedar looks like a desperate attempt to warm up and/or dry clothing .