Canary Spring on the south side of Mammoth Hot Springs has been very active during the past ten years. It has built travertine formations thirty feet high and fifty feet deep. Trees like this are sometimes in the spring’s way. When the hot water first finds the trees, it kills them. After the trees are dead, their branches become brittle, and winter’s heavy layer of frost and ice breaks off many branches. Eventually the spring may embrace the remainder of the tree and seal it in a white stone monument.