Two different places got me interested in this subject. When we were at Moraine Lake in Alberta, I saw a tree trunk along the shore of the lake that was stripped of its bark and showed a spiral pattern in the wood that was exposed. I was rather curious how this would come to be and took some photos of the log before moving on.

When up at Washington Pass a while later, there were some trees that were still upright but that also showed the same pattern of the wood. I wondered whether exposure to wind over time would cause the trees to twist, perhaps, resulting in this sort of pattern in the wood. Alternatively, does it naturally grow that way? Whatever the reason, it makes for some very interesting-looking wood. Anyone know how this happens?