Many of the hot springs in Yellowstone are rainbows of blue, yellow, orange, and red bacteria that thrive on the heat and moisture of the near-boiling volcanic waters.
In this panoramic view of Black Sand Basin in Yellowstone National Park, you can get a sense of how the earth and water beneath your feet is literally boiling up due to the underground lava flows of the volcanic crater upon which it is situated.
Old Faithful is Yellowstone National Park's most famous attraction. Here, just before dawn, it quietly steams as the pressure builds up below the ground in a series of caverns, later to be sprayed sometimes up to almost 200 feet into the air.
