By Dorothy Hoard, January 2014
The Valles Caldera is a volcano in the Jemez Mountains of north-central New Mexico. The caldera is about 15 miles long by 12 miles wide, with a rim about 75 miles around.
The Valles Caldera is the type locality for Resurgent Dome Calderas. It is where geologists studied and described the features that make up the structure.
The rim of the Valles Caldera is the ridgeline right above Los Alamos. Many people used to hike there before it became public land in 2000 and was closed to public access.
Each year, thousands of motorists pause along State Road 4 to view the Valle Grande, presuming that it is the entire caldera. It is not. The best way to comprehend the scope and structure is from the rim. Unfortunately, the resurgent dome, in this case Redondo Peak – second highest point in the Jemez Mountains, obstructs a sweeping view of the entire caldera. This fact necessitates a series of viewpoints around the rim and a trail connecting them.
About 60 percent of the rim is on the Santa Fe National Forest and open to the public. The remainder is on the Valles Caldera National Preserve and is closed to public access. Of interest to Los Alamos hikers is the closed section between Cerro Grande and Cañada Bonita behind the VCNP fence, which has many excellent viewpoints. The east rim and parts of the north and south rims were severely burned in the 2011 Las Conchas Fire. Dead sticks of trees are depressing, but the fire opened up the views. In the long term, when the snags fall and aspen groves cover the slopes, a rim trial will be a true asset.
Advocates hope to establish a trail around the caldera rim.
A hardy band of hikers completed a reconnaissance of the 75-mile rim in January 2014 and produced reports, trip reports, and proposals. To view the results of the rim recon, visit http://vallescalderarimtrail.blogspot.com.