Photo of the central region of the Mammoth Hot Springs. In the background, you can see the distant mountains northeast Wyoming. The terraces are made of the crystalized calcium carbonate, which solidfies when cooled. The Mammoth Hot Springs are a constant tourism spot, and this picture was taken at a stop by the Hot Springs after leaving Yellowstone National Park. This image was taken at 10:58 on August 22 in 2011.