Yellowstone National Park

August 28 - 30, 2006

Mammoth Springs


Mammoth Hot Springs
Mammoth Hot Springs is a series of natural terraces formed by thermal water and mineral deposits. The white rock is made up of travertine deposits, while the other colors are the result of living microorganisms and bacteria that live in the thermal features.
Mammoth Springs

Old Faithful


Old Faithful
Old Faithful is one of more than 300 geysers in Yellowstone. Contrary to popular belief, the time between Old Faithful's eruptions actually varies quite significantly over the years. Currently, the average interval between eruptions is about 94 minutes.

Grand Prismatic Spring
The Geyser Basins
Yellowstone contains the greatest concentration of geysers in the world. The Upper Geyser Basin alone contains one-fourth of the total number of geysers in the world. A number of other hydrothermal features can be found in Yellowstone as well. Besides hot springs and geysers, there are also mud pots and mud volcanoes (formed when hot water mixes with clay) and fumaroles, which emit hot water vapor and gasses.
Saphire Pool


The variety of color found in the springs around the park is attributable to the various types of algae and other microbes that live within the geothermal features. As the hot water leaves the ground and moves outward it cools, creating various temperature zones. Different species of microbes adapt to specific temperature zones, creating the variations of color found in the springs throughout the park.