The Map Below Shows the San Andreas Fault

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The San Andreas Fault is part of the Pacific Rim of Fire. The Pacific Plate is under most of the Pacific Ocean. Here in California the Pacific Plate comes inland to form a transverse fault (the San Andreas Fault) with the North American Plate. The fault is called transverse, because the plates move past each other on a level plain.

North of San Francisco the Fault runs out into the Pacific Ocean. The oceanic plate dips under the land, heating occurs, and magma is formed. This action has formed the cascade volcanoes such as Lassen Peak, Mt. Shasta, Mt. St. Helens and other Cascade Mountains.

Four choices to reach the San Andreas Fault in San Luis Obispo County and Adjourning Counties:

• From San Miguel take the Vineyard Valley Road to the Parkfield and go south.
• From the junction of Highways 41 and 46:
• go south on Davis Road to Highway 58.
• go north on the Cholame Road to Parkfield.
• From Highway 58 go south to the Carrizo Plain National Monument.
• From Highway 166 go north on the Soda Lake Road into the Monument.