After entering Yellowstone National Park, the first of the many interesting geothermal areas you reach is Mammoth Hot Springs, which is a truly remarkable place. Boiling water percolates up from a number of hot springs and cascades down hillsides, forming terraces that are shaded a variety of colors. These have built up over many thousands of years.

This image, taken late in the afternoon, shows three "visual layers": in the foreground, water runoff from one of the major geothermal springs; in the middle ground, some of the terraces that are found all over the Mammoth area; and in the background, some of the mountains that surround the area.