Skip to main content
U.S. flag

An official website of the United States government

Valles Caldera

Find U.S. Volcano

Valles caldera is located in north-central New Mexico in the central Jemez Mountains west of Santa Fe. It is the oldest of three young caldera-type volcanoes in the United States; the other two are Yellowstone in Wyoming and Long Valley in California.

Quick Facts

Location: New Mexico, Sandoval County

Latitude: 35.87° N

Longitude: 106.57° W

Elevation: 3,430 (m) 11,253 (f)

Volcano type: caldera

Composition: rhyolite

Most recent eruption: 40,000 years ago

Nearby towns: Los Alamos

Threat Potential: Moderate*

*based on the National Volcano Early Warning System

The Valles caldera-forming eruption occurred approximately 1.25 million years ago when huge volumes of Bandelier tuff were explosively evacuated from a underground magma storage region. As a result of the "supereruption," the ground subsided along a network of nearly circular faults, called a ring fracture, leaving the caldera, a 20 x 23 km (12 x 14 mi) depression. Resurgent doming of the central caldera floor occurred between 1.25 and 1.22 million years ago, which was immediately followed by additional dome eruptions around the caldera margins up until about 40,000 years ago. These resurgent and ring-fracture eruptions are interlayered with lake deposits, indicating the caldera has been at least partially filled by lakes since its formation. The youngest volcanism occurred in the southwest sector, which coincides with the present-day Valles geothermal system, which is fueled by a magma storage region residing beneath the southwestern caldera.


New Mexico’s answer to Yellowstone: The geological story of Valles Caldera

New Mexico’s answer to Yellowstone: The geological story of Valles Caldera


2018 update to the U.S. Geological Survey national volcanic threat assessment

When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U.S. Geological Survey and its partners. This update

John W. Ewert, Angela K. Diefenbach, David W. Ramsey

An overview of the Valles Caldera National Preserve: the natural and cultural resources

The Valles Caldera National Preserve is one of New Mexico’s natural wonders and a popular area for public recreation, sustainable natural resource production, and scientific research and education. Here, we provide a concise overview of the natural and cultural history of the Preserve, including descriptions of the ecosystems, flora and fauna. We note that, at the landscape scale, the Valles calde
Robert R. Parmenter, Anastasia Steffen, Craig D. Allen

Gas geochemistry of the Valles caldera region, New Mexico and comparisons with gases at Yellowstone, Long Valley and other geothermal systems

Noncondensible gases from hot springs, fumaroles, and deep wells within the Valles caldera geothermal system (210-300??C) consist of roughly 98.5 mo1% CO2, 0.5 mol% H2S, and 1 mol% other components. 3He/4He ratios indicate a deep magmatic source (R/Ra up to 6) whereas ??13C-CO2 values (-3 to -5???) do not discriminate between a mantle/magmatic source and a source from subjacent, hydrothermally alt
F. Goff, C. J. Janik