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October 12, 2025

Sonoma Mountain Geology Walk

students in front of a rocky wall outside

Fairfield Osborn Preserve
Sun, Oct 12, 2:00 pm – 5:00 pm

Register Here

Admission Fees: none


Sonoma Mountain is a part of a tectonic boundary we call The San Andreas. Deep Earth forces have uplifted the mountains & valleys of Sonoma County out of the ocean over millions of years, caused volcanic eruptions, and created topography at the intersection of countless faults. The land exists in its current form because of earthquakes, streams, landslides, fires, and human influence. Join Nicole Myers, Geology Lecturer at Sonoma State University, for a journey through geologic time and history in Sonoma County. We will observe how geology and climate have created the landscape features of Fairfield Osborn Preserve.

Presenter 

Nicole Myers, M.S. in Geological Sciences, developed a passion for understanding the Earth from a childhood fascination with rocks and volcanoes, and now teaches others to appreciate planet Earth. Nicole has been teaching earth science classes, including geology, climatology, & Earth history for more than 20 years. She currently teaches Geology at Sonoma State University (SSU) and through Appreciating Earth, and is the SSU Center for Environmental Inquiry Program & Outreach Specialist. Nicole brings her enthusiasm to the community by offering Earth science field explorations and presentations. 

Logistics 

The maximum hike will be 1.5 miles with a 100-foot elevation gain. We will be walking on trail over uneven, occasionally steep, ground. Walking sticks might be helpful.

  • Fairfield Osborn Preserve is a 15-minute drive form Sonoma Sate's main campus, on Lichau Road in Penngrove. Driving directions will be provided in your registration confirmation and email.
  • Parking is limited so please consider carpooling, and park close together.
  • The preserve gate will be unlocked 15-minutes prior to the start time of the event. The preserve gate will be locked 15-minutes after the start of the event time. It is not possible to join the event late or to leave the event early.
  • We will meet outside at the Federated Indians of Graton Rancheria Learning Center, which is across the footbridge on the east side of the parking lot.
  • Participants must sign a waiver upon arrival. All minors must be accompanied by a legal guardian for the entire event.
  • Pets and smoking are not permitted.
  • This is a rain or shine event.
  • No previous experience or knowledge is required to participate.

What to Bring

Please bring rain, sun, and insect protection as needed, a full water bottle and snack, and sturdy footwear for hiking. Layered clothing & long pants are recommended.

A sink for handwashing, potable water and restrooms are available on site.

How to Sign Up

See registration link above. Each person should register separately. This event is free of charge.

About the Center

Sonoma State University’s Center for Environmental Inquiry empowers university students to work with community members on the environmental challenges of the North Bay. Our mission is to create an engaged and environmentally ready society, one where all people have the skills to find solutions to the challenges facing our earth. SSU Preserves are open to everyone engaged in education or research. Reservations are required.

Contact Email: [email protected]