The San Andreas fault in Sonoma and Mendocino counties

This two-day trip explores the northern San Andreas fault in the Gualala area between Fort Ross and Point Arena (Fig. 1). The first stop overlooks the Golden Gate Bridge and includes a discussion of its in-progress seismic retrofit. Several subsequent stops are at paleoseismic sites on the San Andreas fault. The stop at Annapolis Road includes a short hike along the fault through the redwood forest. This section of the fault is locked and has not moved since the 1906 earthquake. Additional stops visit Quaternary marine terraces and include discussion of associated tectonic deformation.