Pinnacles National Park has a twin near the city of Santa Clarita some 200 miles to the south, the Neenach Volcanic Formation. Born of fiery rhyolite lava flows some 23 million years ago, they were ripped apart in their youth by the notorious San Andreas Fault. Pinnacles has been making its way north ever since: Inch by inch and earthquake by earthquake.

Noted for its personality-plus pinnacles, talus tunnels, and wild flowers, the region was declared a National Monument by Teddy Roosevelt in 1906. Legislation by Congressman Sam Far from the Monterey/Carmel area in 2012 led to its being established as a national park. (Sam, like me, was an early Peace Corps Volunteer. For a brief time, we worked together in the Western United States as Peace Corps Recruiters.)

The Pinnacles are something of a poster-child for Plate Tectonics. While the existence of the plates and their impact on geology and geography is a well-known and accepted theory today, the history of the concept is relatively recent. I remember sitting in a geology class I took at UC Berkeley in 1964 when the professor came in almost glowing. “I have something to share,” he declared, “please understand that it is still a theory. I’m late because I was just in a meeting where substantial evidence was given that the surface of the world is made up of giant plates that separate, crash into each other, move along each other’s edges.”

The close relationship between the rocks and minerals of Pinnacles and the Neenach Volcanic Formation helped to show that the Pacific Plate and North America Plate have been moving past each other via the San Andreas Fault for 20 some million years. Pt. Reyes National Seashore north of San Francisco, where we are now, also sits on the San Andreas Fault and is another example of the movement. In fact, our campground is sitting on top of the fault. Our fervent hope is that it stays in place, at least for another week!