Which volcanic caldera in Wyoming formed during a supereruption about 631,000 years ago?

The Yellowstone Caldera in Wyoming formed during a supereruption about 631,000 years ago.

That eruption, called the Lava Creek eruption, expelled an enormous volume of volcanic material and created a caldera roughly 55 by 72 kilometres across. The depression later became part of the Yellowstone volcanic field, which has also produced smaller eruptions and extensive lava flows.

Yellowstone is not a single cone-shaped volcano. It is a large volcanic system powered by a hotspot beneath the North American Plate. The hotspot’s earlier activity helped form the nearby Henry’s Fork Caldera and Island Park Caldera, while the Yellowstone system experienced major eruptions before the Lava Creek event, including the Huckleberry Ridge eruption about 2.1 million years ago.

The caldera is often confused with Yellowstone National Park as a whole, but the park is much larger. Yellowstone’s famous hydrothermal features—including Old Faithful, hot springs, mud pots, and geysers—are heated by the same underlying volcanic system.