At the Mammoth Hot Springs area in Yellowstone National Park, over time hot water from the springs cooled and deposited calcium carbonate on terraces. Algae living in the warm pools have tinted the travertine in shades of brown, orange, red and green. This dead tree grew during inactivity of the springs and was killed when the calcium carbonate carried by the spring water clogged the tree's vascular system. Interestingly, recent earthquake activity has shifted the spring’s vents, causing the terraces to dry out.

Finalist - Plants & Planet