The Yellowstone Plateau volcanic field developed through three volcanic cycles spanning over two million years and including two of the world's largest known eruptions.


The >2450 km3 (588 mi3) Huckleberry Ridge Tuff erupted about 2.1 million years ago, creating a large, approximately 75 km (47 mi) wide, caldera and thick volcanic deposits. A second cycle concluded with the eruption of the much smaller Mesa Falls Tuff around 1.3 million years ago. Activity subsequently shifted to the present Yellowstone Plateau and culminated 640,000 years ago with the eruption of the >10003km (240 mi3) Lava Creek Tuff and consequent formation of the 45 x 85 km (28 x 53 mi) caldera. Large volumes of rhyolitic lava flows (approximately 600 km3 (144 mi3) were erupted in the caldera between 180,000 and 70,000 years ago, distributed primarily along two north-south alignments of vents. No magmatic eruptions have occurred since then, but large hydrothermal explosions have taken place during the Holocene, including near Yellowstone Lake. Uplift and subsidence of the ground surface is centered on two uplifted regions (the Mallard Lake and Sour Creek resurgent domes). Large earthquakes occur just off the plateau along the nearby Teton and Hebgen Lake faults, the latter of which ruptured in 1959 (Ms = 7.5), causing considerable damage to the region. Yellowstone is presently the site of one of the world's largest hydrothermal systems including Earth's largest concentration of geysers.


Date published: April 12, 2021

Yellowstone’s caldera, resurgent domes, and lava flows—volcanic giants hiding in plain sight

While geysers and hot springs are relatively easy to find in Yellowstone, what about the caldera, and the lava flows and the two massive resurgent domes that formed after the caldera erupted?  They’re there.  You just need to know where to look.

Date published: April 5, 2021

Yellowstone’s Cool Thermal Areas

Yes, some of Yellowstone’s thermal areas are cool—as in, no longer hot.  Cooling is part of the “life cycle” of a thermal area.  And just as it’s important to keep track of where thermal areas warm up, it’s also important to keep track of where they are cooling down.

Date published: March 29, 2021

Arid southwest landscapes dotted with the bright lights of a …. lava fountain!?

Volcanoes in Iceland, Italy, and Guatemala have put on displays that are captivating audiences worldwide. But did you know that the same sort of activity could also occur in the southwestern United States?

Find a U.S. Volcano