Rocks on the Move at Point Bonita

Park Ranger Mayeda examines pillow basalt on Black Sands Beach in the Marin Headlands
Stacks of pillow basalt at Black Sands Beach in the Marin Headlands

NPS Suzanne Garcia

Rocks on the Move at Point Bonita, Keepers of the Light and Land brings students to the Point Bonita Lighthouse trail, a location with both maritime and geologic significance. The high cliffs and volcanic rocks form a dramatic backdrop for students to work collaboratively to produce a simplified version of F. Leslie Ransome's 1893 geologic map of Point Bonita. Students work in teams to answer their questions about the changing landscape of an investigation site of their choosing.

By the end of the program, students have the opportunity to recognize evidence of weathering and erosion on Franciscan Complex rocks, and to consider the reasons why some of the Point Bonita pillow lavas remain essentially unchanged since the 1870s, while other sections of the trail erode and slide frequently. Students speculate on how the continued processes of weathering, erosion, human activity and climate change may impact the Point Bonita landscape in the future, and how these same processes impact their communities.

To learn more about the Rocks on the Move experience at Point Bonita, click here for our annotated curriculum guide, with links to lesson plans and activities.

Click here to see the Rocks on the Move geologic investigations at Point Bonita.

Click here to take a virtual tour of Point Bonita geology (English).

Click here to take a virtual tour of Point Bonita geology (Spanish).

Contact the Park

Mailing Address:

Golden Gate National Recreation Area
Building 201, Fort Mason

San Francisco, CA 94123-0022

Phone:

(415) 561-4700
Pacific West Region Information Center (415) 561-4700 Special Event & Commercial Film Permits (415) 561-4300

Contact Us