The geothermal areas of Yellowstone include several geyser basins in Yellowstone National Park as well as other geothermal features such as hot springs, mud pots and fumaroles.
The number of thermal features in Yellowstone is estimated at 10,000 and 200 to 250 geysers erupt in Yellowstone each year, making it the place with the highest concentration of active geysers in the world, thanks to its location in an ancient caldera.
The various geyser basins are located where rainwater and snowmelt can percolate into the ground, get indirectly superheated by the underlying Yellowstone hotspot and then erupt at the surface as geysers, hot springs and fumaroles.
Due to the Yellowstone Plateau's high elevation the average boiling temperature at Yellowstone's geyser basins is 93 °C. When properly confined and close to the surface it can periodically release some of the built-up pressure in eruptions of hot water and steam that can reach up to 120 m into the air.
Photographer © Karin Van Couwenberg