Doublet Pool

Doublet Pool is a hot spring in Yellowstone National Park’s Upper Geyser Basin, within one of the park’s most active geothermal areas. About 8 feet deep and near 194.4 degrees Fahrenheit, it has a scalloped rim of geyserite, the siliceous mineral deposited around thermal features. Though mainly a hot spring, it can erupt for up to 8 minutes. It is especially known for the right-hand pool’s pulsing over its vents about every two hours, along with vibrations, surface waves, and a thumping motion caused by collapsing gas and steam bubbles deep underground. These subtle movements distinguish it within Yellowstone’s geothermal landscape.

Wyoming · United States