Valles Caldera National Preserve Added To List Of Parks With ‘Significant Thermal Features’

Scientific core hole VC-2A erupting steam and geothermal brine at Sulphur Springs, western Valles caldera, May 1987. The fluid originates from a 210 °C crack in intracaldera Bandelier Tuff at 490 m depth. Geothermal gases reaching the surface from this reservoir fluid form fumaroles and create natural sulfuric acid that reacts with rock. A wasteland of kaolin, sulfur, gypsum, alunite, pyrite and other interesting minerals surrounds the hot spring area. Sulphur Springs recently became part of Valles Caldera National Preserve. Photo by Fraser Goff


The National Park Service added Valles Caldera National Preserve to the list of parks with “significant thermal features” under the Geothermal Steam Act. The Preserve is only the 17th park unit to make the nationwide list. Valles Caldera was nominated for recognition in 2016, and following a public review and comment period, received nearly unanimous public and tribal support.

“This designation provides well-deserved recognition of these special volcanic features and will help the preserve access resources to support their protection and promote scientific study and educational programs for the public,” said Valles Caldera Supt. Jorge Silva-Bañuelos. The designation can be used to legally limit drilling and geothermal development in areas nearby that might damage thermal activity inside the preserve.

Valles Caldera National Preserve, located in the center of the Jemez Mountains volcanic field in northern New Mexico, contains numerous volcanic geothermal features, including sulfuric acid fumaroles, mud pots, hot springs, and cold springs. In one site alone, Sulphur Springs, there are seven named sulfuric acid springs within a 20-acre area. These springs include such colorful descriptive names as Kidney and Stomach Trouble Spring, Footbath Spring, Ladies’ Bathhouse Spring, Laxitive [sic] Spring, Turkey Spring, Lemonade Spring, and Electric Spring. No other sulfate-based acidic hot springs occur in the State of New Mexico, and they are rare throughout the rest of the United States. 

The listing process is explained at Federal Register / Vol. 86, No. 62 / Friday, April 2, 2021 / Notices.