Escapees January-February 2023

skp stops

When you think of Palm Springs, what might come to mind are movie stars, tall palms, sunning poolside, tennis, golf and horseback riding, and rightfully so. B ut the west side of Palm Springs has yet another treasure: Mount San Jacinto. That mountain is the “backdrop” of Palm Springs and it has a unique ancient geologic history. Back in the Mesozoic Era about 150 to 80 million years ago, a volcanic intrusion occurred in the region. That magma cooled, crystallized and eventually metamorphosed into granitic rock batholiths. Over the millions of years since then, tectonic action between the North American Plate and the Farallon Plate exposed the granitic batholiths and formed the Peninsular Range that begins just north of Palm Springs and continues into Baja California, Mexico. About 30 million years ago, the Paci fi c Plate and North American Plate started to form the boundary that we now call the San Andreas Fault. Then, even more tectonic activity created the uplifting that makes Mount San Jacinto. The mountain is actually still “growing.” Although primarily granitic rock, Mount San Jacinto has some pre-existing rock that was originally sedimen tary, but that metamorphosed from heat and pressure during the Mesozoic times. Gneiss and schist are present. To get a good view of this massive mountain, many take a ride on the Palm Springs Aerial Tramway which goes up from 2,643 feet at the start of the mountain’s Chino Canyon to a Tram station at the top at 8,516 feet. The Tram gives access to the Mount San Jacinto State Park where over 50 miles of hiking and primitive camping are available (permits required, available at the Ranger Station). The Hidden Divide Natural Preserve can also be reached—a 255-acre habitat for More Than Swimming, Tennis And Golf Palm Springs— Mount San Jacinto 25905 Highway 243, Idyllwild, CA 92549, 951-659-2607 www.parks.ca.gov/?page_id=636

The Palm Springs Aerial Tramway car.

rare, endangered and endemic plants and animals. The Preserve is protected by restricted recreational use with hiking only on the existing trails and no off-trail hiking or camping within the Preserve. Another impressive view of the mountain is to drive Highway 111 northward toward Interstate 10, about fi ve miles out of Palm Springs, to gaze at the massive north east face of the mountain and its fault scarp between the San Jacinto Fault to the west and the San Andreas Fault to the east. That squeezing and the accompanying earthquake movements are pushing up the mountain and have already created what is one of the steepest escarpments in North America, gaining about 10,000 feet of vertical elevation in only a few miles. Of course, weathering and erosion are also occurring so the layers atop the massive batholiths are breaking down and letting the rock layers below expand and then fracture and crack. So, set down the tennis racquet, golf clubs or reins, slip into your hiking shoes, and let Palm Springs show you the unique and fascinating mountain that is its “back wall.” It’s an impressive mountain, well worth the look! Article and photo by Dr. Stephenie Slahor, Guest contributor

29

January/February 2023 ESCAPEES Magazine