The Valles Caldera National Preserve is a national preserve located in northeastern Sandoval County and southern Rio Arriba County, just west of Los Alamos. It protects a large portion of the Valles Caldera, an area of significant geological, ecological and cultural interest. It has a land area of 89,216 acres and until 2015 was administered by the Valles Caldera Trust with offices in Jemez Springs.