A Tectonic Masterpiece
California has more national parks than any other state in the union with nine – Yosemite, Joshua Tree, Death Valley, Sequoia, Kings Canyon, Lassen, Redwood, Channel Islands, and the one that few people even know exists, Pinnacles National Park.
Pinnacles National Park protects 26,685 acres of the southern region of the Gabilan Mountains east of the fertile Salinas Valley. The area became a national monument in 1908. In the 1930s, the Civilian Conservation Corps built a series of trails through the monument, trails which are still in use today. In 2013, Pinnacles was designated a national park. It is the seventh smallest of the national parks, and in 2019, logged 177,224 visitations ranking it 50th in park visitations. The twelve parks less visited are mostly in remote Alaska or off the shores of the U.S.
The park is known for its fabulous rock formations that include towering monoliths, twisted spires and talus caves.
The rock formations form a spine that divides the park into two halves, the west district and the east district. There is no road that connects the two districts, but you can hike from one district to the other. To get from one entrance to the other by car, you must drive around the park which takes about two hours.
The western district is reached via CA-146 from the town of Soledad. This road is steep, very winding, and narrow, often only 1 to 1.5 lanes wide. I would not recommend trying to access the western section of the park in an RV or towing a trailer. The eastern district can be accessed from Hollister via Highway 25. The road to the eastern entrance of the park is much more RV/trailer friendly.
The ecosystems of the two sides of the park are very different. The western district is more arid with easy access to the rock formations. The eastern side is less arid with springs, creeks, a reservoir, and riparian habitats.
The rock features for which the park is named provide an excellent example of plate tectonics. They are remnants of an ancient stratovolcano called Neenach.
About 23 million years ago, a more dense oceanic tectonic plate called the Farallon Plate began to slide beneath the western edge of the North American Plate in a process called subduction (diagram courtesy of NPS). The friction caused by subduction results in two things, tension cracks and the melting of the subducting plate. The melted material rises to the surface through the fissures often forming a volcano. The subduction of the Farallon Plate generated a large amount of volcanic material.
It is interesting that the narrow band of spires, monoliths, and craggy features seen in Pinnacles bear no resemblance to the surrounding landscape. The question is why?
As the Farallon plate subducted, the next plate on the conveyer belt, the Pacific Plate, collided with the western edge of the North American Plate breaking off a fragment of the North American Plate which became attached to the Pacific Plate and generating a huge crack. Volcanic material poured through the crack creating a volcanic field about 15 miles long and 8,000 feet high. This big crack is what we know as the San Andreas Fault which today looks like an 800-mile long valley extending from the Mendocino coast south to the San Bernardino Mountains and the Salton Sea.
The North American and Pacific plates began to slide past each other along this crack which is called a strike-slip or transform fault (diagram courtesy of NPS). Most of California’s population lives on the Pacific Plate and is riding it northwest at a rate of about 3 inches per year while the rest of the population of North America is riding the North American Plate southward at about 1 inch per year.
The volcanic material that erupted through the crack was deposited on both sides of the fault but became separated due to the opposite movements of the plates. Scientists have been able to determine how this all occurred because the breccia rocks found in Pinnacles National Park are found in only one other place which is found 195 miles to the southeast in northern Los Angeles County in a geological formation called the Neenach Formation. This formation lies on the eastern side of the fault line. The fantastic features we see in the park are the results of erosion of these volcanic rocks by wind and rain.
The monoliths, spires and crags are not the only interesting geologic features within the park. Pinnacles also has a number of caves. These caves are neither typical caves that are below ground and often filled with interesting formations nor lava tube caves.
The caves in Pinnacles National Park are talus caves which form from deep, narrow gorges or fractured rocks which become caves when huge boulders falling from above wedge in the fractures before reaching the ground. It is believed that these rockfalls occurred during the last Ice Age.
The park has two main cave areas – the Bear Gulch Caves in the East District, and the Balconies Caves in the West District. There are a few other small talus caves scattered about the park. During the Depression of the 1930s, the CCC built trails through the caves. These trails include stairways and bridges that allow navigation without the use of ropes and ladders. These trails are still the ones in use today. Unfortunately, all caves within the park currently are closed to visitors as COVID prevention measures.
Another of the features of Pinnacles is the presence of the endangered California Condor. In 1979 there were only 25-35 of these birds in the wild and by 1987, the last wild condor was removed from the wild so the only remaining members of the species were housed in captivity to try to save them from extinction. Through captive breeding and release into the wild, the goal was to increase the numbers and return them to the environment. By 2017, 170 animals had been restored to the wild in California.
Condors are scavengers that eat only dead animals. They are not handsome birds with bald heads, hooked beaks, muscular necks, large flat feet instead of talons and 9.5 foot wingspans. Bald heads keep them cleaner while feeding on rotting animals. Strong necks and hooked beaks are needed for pulling and tearing chunks of meat off a carcass. Flat feet making standing on the ground easier as they rip chunks off the carcass. Condors are related to the more common, smaller Turkey Vulture. Other than size, you can distinguish the two species by looking at the underside of the bird as they glide above you. An adult condor has a white triangle on the leading edge of the underside of the wings. (Photo courtesy of Wikimedia Commons.)
I did get to see two condors in the distance while climbing to the high peaks, but they were too far away to get a decent shot since I didn’t have my telephoto lens.
You can get a nice overview of the park if you watch this video produced by the national park.
There are 32 miles of trails that climb among rock formations, through talus caves, and along shaded creeks. I only had time to do two hikes in the west district.
Trail #1 Prewitt Point Trail. This is an easy, accessible trail that is 0.9 mi. roundtrip with an elevation change of only 70 feet, You reach the main overlook at 0.4 miles. From the overlook, there is a 0.25 mile loop. This trail gives distant views of the pinnacles and the Hain Wilderness. There is essentially no shade on this trail so during late spring, summer and early fall, this is a hot, dry walk during the middle of the day and afternoon. This is a good introductory trail.
Trail #2. Juniper Canyon Loop. This trail is rated as strenuous. It is a 4.3 mile loop with an elevation change of 1,215 feet. The trail starts out in the chaparral as a fairly flat shady path along a seasonal stream.
The majority of the trail is composed of steep switchbacks which take you to the heart of the High Peaks, the rocky centerpiece of pinnacles where you circle through the rock formations along a steep and narrow section of the High Peaks and Tunnel Trails. You then return to the canyon via the switchbacks.
There are a number of things of which to be aware if you are going to hike in Pinnacles National Park.
- Daytime temperatures in summer and early fall often climb to over 100 degrees. You should wear a hat and appropriate clothing as protection from the sun.
- Beware of dehydration. Carry and drink at least one liter of water per hour.
- Most trails are rough and rocky, wear footwear with good traction and ankle support.
- There is no cell phone service in the park.
- If you are going to explore talus caves, bring a bright flashlight. The light of a cell phone is insufficient.
- Watch where you sit, step or place your hands due to the presence of poison oak, stinging nettles, and rattlesnakes.
I recommend this park if you want to avoid the crowds that visit California’s more well known parks. I plan to go back and explore the east district of the park next winter.
I had no idea this park even existed. What a wonderful introduction to a place that really looks interesting.