Valles Caldera National Preserve protects much of a 13.7-mile wide extinct volcanic caldera in the Jemez Mountains, just west of Los Alamos.  

 

The preserve encompasses almost all of the volcanic caldera created by a spectacular volcanic eruption about 1.25 million years ago. The caldera is dormant, but not extinct, and still displays signs of volcanic life with hot springs and boiling sulphuric acid fumaroles. The juxtaposition of large grassland meadows, or valles in Spanish (we explored the largest, Valle Grande, during our visit), surrounded by rounded forest covered volcanic domes provides the distinctive natural landscape that led to the name of Valles Caldera.

 

The lowest points in the preserve, located in the valley floors, are 8,500 feet above sea level; the highest point, at 11,253 feet above sea level, is Redondo Peak, a resurgent lava dome located entirely within the caldera.

 

The preserve was created in July 2000.

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National Park Service