With half of the earth’s geothermal features, Yellowstone holds the planet’s most diverse and intact collection of geysers, hot springs, mudpots, and fumaroles. Its more than 300 geysers make up two thirds of all those found on earth. Combine this with more than 10,000 thermal features comprised of brilliantly colored hot springs, bubbling mudpots, and steaming fumaroles, and you have a place like no other. Geyserland, fairyland, wonderland--through the years, all have been used to describe the natural wonder and magic of this unique park that contains more geothermal features than any other place on earth.

Yellowstone’s vast collection of thermal features provides a constant reminder of the park’s recent volcanic past. Indeed, the caldera provides the setting that allows such features as Old Faithful to exist and to exist in such great concentrations.

Descriptions and explanations of the processes involved in the functioning of the following geothermal features is just a click away.

• Hot Springs
• Mudpots
• Fumaroles (Steam Vents)
• Mammoth Hot Spring Terraces
• Geysers
• Yellowstone Hotspot Theories
• Ground Truths

Technical information is available from these Non-NPS sources.
Yellowstone Volcano Observatory - U.S. Geological Survey site
Yellowstone Geysers - courtesy of David Montieth & Contributors
Yellowstone Hotspot - courtesy of Bob Smith, University of Utah