West Thumb Geyser Basin

basin, Yellowstone national Park, United States

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July 20, 2026

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The West Thumb Geyser Basin is a notable hydrothermal area located on a protrusion on the western side of Yellowstone Lake within Yellowstone National Park, United States. This basin was formed by a volcanic eruption approximately 150,000 years ago within the larger Yellowstone Caldera.123

The West Thumb Geyser Basin is characterized by its hot springs and geysers, which are a result of groundwater interacting with magma or hot igneous rocks beneath the surface. It was one of the first hydrothermal features in Yellowstone to be documented, with a description published in 1827. The basin contains various thermal features, including hot pools and geysers, and is situated at an elevation of 7,730 feet (2,356 meters).421

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Yellowstone Lake
…amount flowing in from the West Thumb Geyser Basin), the lake’s water remains cold throughout the year. Ice begins to form on its surface in late December or early January, and it remains frozen until late May or early June.
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…amount flowing in from the West Thumb Geyser Basin), the lake’s water remains cold throughout the year. Ice begins to form on its surface in late December or early January, and it remains frozen until late May or early June.
Read More