One of our nation's oldest national monuments is set to become
our nation's newest national parks, and I couldn't be happier about it! Assuming the legislation is signed by President Obama, Pinnacles National Park will be one of the most geologically interesting parks in the system for a number of reasons, not the least of which is that it lies on a major plate boundary, and provided critical evidence for understanding the movement of the San Andreas fault. It doesn't hurt that it is also one of the most scenic portions of the central Coast Ranges of California (mind you, Big Sur is beautiful too, but remarkably no part of Big Sur is a national park or monument).
![]()
Pinnacles was established in 1908 by Theodore Roosevelt under the auspices of the National Antiquities Act, which was one of the wisest acts of Congress ever. The act allowed presidents to establish monuments without congressional approval, and without it we might never have had Grand Canyon, Zion, Petrified Forest, Death Valley, or Joshua Tree National Parks, because all of them were established as monuments at first, often over local opposition. It often took decades, but Congress would eventually come to its senses and make the monuments into national parks, as it did this week with Pinnacles.
I have been taking geology classes on field studies trips to Pinnacles National Monument now for 24 years, and it has been a significant part of my blog explorations of California (
click here for a sampling of some of my descriptions of the region). The geological attraction of the park is the 22 million year old extinct stratovolcano that erupted on top of the San Andreas fault in southern California near Palmdale and Lancaster in the Mojave Desert. Subsequent movement along the fault has carried the Pinnacles half of the volcano 195 miles northwest to its present location in the central Coast Ranges (the other half, called the Neenach volcanics, aren't nearly as scenic).
The ancient volcano has eroded into an intricate maze of spires and deep slot canyons. The High Peaks Trail loop, which traverses the most rugged part of the Pinnacles, is close to the top of my list of favorite hikes in the world (and mind you, that is a list that includes Angels Landing in Zion, Delicate Arch in Arches, the Grand Canyon, and the Burgess Shale in Canada). The slot canyons have in places been completely covered over by gigantic boulders, forming
talus caves. One is a quarter mile long, and includes an underground waterfall.
The park has some great wildlife and botanical attractions to complement the wonderful geology. To this day it remains the only place where I've seen a wild bobcat. It is also home to one of the few populations of the California Condor, and they can often be viewed from the visitor center on the east side of the park.
Pinnacles National Monument was enlarged several years ago, and there is a proposal to incorporate ranchlands to the east across the San Andreas fault. This would be an excellent idea if the funding could be found to do it. The park is already an example of a transform boundary, and expansion would add rocks that formed in the Franciscan subduction zone that effected the region during Mesozoic and early Cenozoic time.
On a political note, I want to thank Representative Jeff Denham for co-sponsoring the legislation that is allowing the monument to become a park. Denham represents my district, and on most issues (really, all of them) we greatly disagree. But on this, he did good.
Pinnacles National Monument-soon-to-be Park can be accessed by paved roads from the west out of Soledad and King City, and from the east on roads out of Hollister and San Juan Bautista (no roads cross the monument). A campground is available on the east side of the park, and 30 miles of trails are available. The park is a popular technical rock-climbing area. There are only nine days left to comment, but an extensive management plan is being considered at this time.
Information can be found by clicking here.
