Pinnacles — The Ancient Volcano
A Volcano Split by the San Andreas Fault · San Benito County
Pinnacles National Park is the eroded remnant of a volcanic field that erupted 23 million years ago — in what is now the Lancaster area of Southern California. Over millions of years, the Pacific Plate carried the volcanic rock 195 miles northwest along the San Andreas Fault to its present location. The spires and crags that make Pinnacles so dramatic are the result of 23 million years of erosion.
Timeline
The Neenach Volcano Erupts
A chain of volcanoes erupts in what is now the Mojave Desert near Lancaster, California. The lava flows and volcanic debris accumulate into a large field of rhyolite and basalt. Over millions of years, the Pacific Plate — moving northwest at about 2 inches per year — carries the volcanic remnants 195 miles to their current location.[1]
The Chalon People
The Chalon Ohlone people lived in the valleys and foothills around the Pinnacles for centuries, using the area for hunting and as a travel route between the coast and the San Joaquin Valley. Rock art in the area attests to long human presence in the landscape.[2]
Pinnacles National Monument
President Theodore Roosevelt designates the Pinnacles area a National Monument in 1908, recognizing its unique geological and ecological character. The monument is managed by the Forest Service, then later the National Park Service.[2]
National Park Status
President Barack Obama signs legislation upgrading Pinnacles from a National Monument to a National Park on January 10, 2013 — making it California's ninth and the nation's 59th national park. The park is a critical sanctuary for the endangered California condor recovery program.[2],[3]
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Sources
Citations behind the dates, names, and numbers on this page.
- 1National Park Service — Pinnacles Geology
Geologic history of the Neenach volcanic field, San Andreas fault movement, and Pinnacles rock formations.
- 2National Park Service — Pinnacles History & Culture
Official history of the monument's 1908 designation and cultural history of the Chalon people.
- 3National Park Service — Pinnacles Present Day
National-park designation, 2013 upgrade, and California condor recovery program.