NOT a swimming pool!!
One of the most fascinating things about Yellowstone is how bare the nature is on the west side compared to the east. There was a big fire a few years ago and that has affected the west side the most. On the west side is also where you find most of the hot springs and the geysirs.
This tree, believe it or not, fell down just 10 seconds after we had passed. Luckily nobody was hit by the fallen tree, but two women were standing very close by talking to eachother. They posed with the tree afterwards, I guess that is what you do when you realize how lucky you just were! I lived to tell the story..