The first-ever unscheduled hike up a lava dome inside the Valles Caldera National Preserve has been offered to the public: an 8-mile journey up lush South Mountain, open every day in the summer, for $5-$10.
South Mountain (elev. 9,795) forms part of the the western edge of the Valle Grande. Once the second (and final) cataclysmic eruption in the Jemez Mountains took place 1.2 million years ago (the first being the eruption that formed the Toledo Caldera about 1.6 million years ago), the earth collapsed on itself along a ring fracture, creating the Valles Caldera. Many different ring fracture domes (also known as lava domes) were formed over the next 700,000 years along the fracture, as explained by the “toothpaste tube model” of eruptions. These domes gradually erupted in a roughly counterclockwise manner, beginning with Cerro del Medio and Cerro Abrigo, which form the northern boundaries of the Valle Grande. The two final ring fracture domes created — both about 500,000 years ago — were South Mountain, as well as relatively tiny, 200-foot-tall Cerro la Jara, which rises from the Valle Grande like an island in the tall grass (check out this view from the sky, which features Cerro la Jara as a bump in the middle of the Valle Grande, with South Mountain directly to its left. Also, check out the Geology section of VallesCaldera.com’s FAQ page for more information on the geology of the Valles Caldera).
This is the first unscheduled hike up a ring fracture dome that the Trust has offered. The three unscheduled hikes offered currently allow visitors to descend into the Valle Grande (the Valle Grande Trail), ascend the south rim of the Caldera (the Coyote Call Trail) and circumnavigate Cerro la Jara (the La Jara Trail). As mentioned above, Cerro la Jara is also a ring fracture dome, but at this time visitors are not permitted to climb that dome’s slopes. Visitors can hike the ring fracture domes Cerro Abrigo and Cerro Seco, but these are by reservation only, and hikers must be driven in a Preserve van out to these peaks’ trailheads (click here to see maps of all of the hikes offered by the Preserve).
According to the map of the South Mountain hike (which can be seen by clicking here), visitors can ascend to a maximum altitude of about 9,475 feet, about 320 feet beneath the dome’s summit. On the dome, visitors are certain to be treated to stunning views of the Valle Grande, the Caldera’s south and east rims, as well as ring fracture domes Cerro del Medio and Cerro Abrigo. The hike is designated as “moderate to difficult,” with an elevation gain of 1,000 feet.
This hike will be offered seven days a week during the summer recreation season, which lasts until Sept. 30 (with some exceptions – check the calendar to be sure).
You can drive down to the Valle Grande Staging Area, which is two miles from Highway 4 in the Valle Grande, and begin your hike there (get directions to the staging area by clicking here). This option, which takes about 8 miles, costs $5. Alternatively, you can pay $10 total and be driven to the Ranch Headquarters area (click here for a view from the sky of Ranch HQ), which cuts about 2 miles off of your hike.
The verdant, forested slopes of South Mountain will likely offer fantastic scenery and a memorable experience to its visitors. This type of unscheduled activity is one example of the sort of access to our National Preserve that many New Mexicans have been hoping for. The Trust should be applauded for opening up a new piece of this stunning volcanic landscape that has never been available to the public.
