Hot Stuff: Geology of Amboy Crater (UCRX, .5 units)

Southern California is known for its trembling fault lines, quirky rock outcroppings, and majestic mountains. But we’ve got other geological wonders too — like volcanoes! One of the finest examples of a cinder cone you’ll ever stumble across is located right here in the Mojave Desert: Amboy Crater. Learn about this designated National Natural Landmark and other dormant volcanoes that stretch across the desert in this full-day geology lesson. Experience endless lava fields and learn about the formation of the Swiss-cheese-like appearance of the rock as you hike the rim of this iconic crater. 4-mile round trip to the rim of the crater and back.

• This class is held at the Amboy Crater in the Mojave Trails National Monument.

• This excursion is suitable for intermediate to experienced hikers. No geology expertise is required.

• No park pass is required.

• No meals or equipment are provided.

• Participants are responsible for their own transportation. Carpooling is encouraged.

Activity level: This class is strenuous. It requires 5 or more miles of walking, which may include several hours outdoors in the elements, significant elevation gain, and variable terrain. You will need personal equipment.

Required items for participants: 

• Water, between 3 and 4 liters per person for a full-day outing

• Food and snacks

• Closed-toe athletic shoe

• Sun protection: hat, sunglasses, sunscreen

• Appropriate clothing 

• Daypack

• Notebook and pencil

• Compass/GPS device

• Camera

• Binoculars 

• Field guides 

• “Roadside Geology of Southern California” by Arthur Gibbs Sylvester and Elizabeth O’Black Gans. Available at the Joshua Tree National Park visitor centers or joshuatree.org

Participants earn .5 units toward a Desert Ecology & Conservation Certificate. Eligible Desert Institute classes can be taken for fun or for credit toward a certificate. To earn the certificate, you must complete 12 units of eligible classes within three years. We offer a variety of classes each season! The certificate is available through UCR Extension. You do not need to be a current student in any academic program to earn the certificate. Units do not contribute to any academic degree.

Your instructor: Alessandro Grippo, Ph.D., Geological Sciences, University of Southern California, has done research and taught geology, oceanography, stratigraphy, environmental geology, and field classes at Santa Monica College and several California State University campuses. Alessandro has a keen interest in the geology of the American southwest and loves being out there exploring, learning, and sharing his passion for Earth and its history. 

Alessandro also worked in the oil industry between his M.S. and his Ph.D., was a fellow faculty member at NASA-JPL for one year, and brought his students from Catalina Island to Nevada, from the Salton Sea to northern California. His interests and study, together with his passion for photography, took him throughout Europe and the Americas looking for geological features.

Photo credit: JTNPA/Reilly Powell