So far, I think this thread is bearing out its original purpose. It was/is, to merely document this stuff that keeps popping up in forested areas in N. America, noting that no plausible evidence of human agency in the creation of it has been advanced, the purpose behind its creation is uncertain, and the creation of it by natural causes is just as unlikely. That there continues to be a correlation between reports of BF encounters in the proximity of these structures makes this phenomenon all the more intriguing.
So, to sum it up:
1. These are there.
2. They are either beyond the physical capability of humans without mechanical assistance, or would have no discernible purpose if done in that manner.
3. Wind, rain, ice and snow are inadequate explanations.
4. They are found in the proximity of areas where BF sightings have been reported.
5. There are consistent patterns of construction across time and vast geographic areas.
6. Their purpose is unknown.
7. Their origins remain unexplained.
I would welcome any discussion of these points that is evidence based, and not just rank opinion, or any other points germane to the subject, and which I've failed to note.