While in California on business last week my coworkers and I found time for a brief visit to Pinnacles National Monument. Nestled in the Gabilan Range in the west-central part of the state, this site preserves a wonderland of scenic and fascinating volcanic rocks. It also preserves a chaparral ecosystem and hosts a number of critically endangered California condors.
With our limited time we opted to hike up the High Peaks Trail through some of the most impressive pinnacle rocks. The oldest rocks are granitic and form the base of the entire area.
Around 23 million years ago a volcano erupted here, extruding large amounts of material that now form the Pinnacles Volcanic Formation. The rhyolitic magma was viscous and oozed in slow-moving lava flows, accumulating in thick masses around the vents. Landslides around the steep slopes broke apart and crushed rock into finer pieces. At times ash was ejected from the vent, settling over the area. Accordingly, the resulting rocks found here are largely rhyolite, breccia, and tuff.
Since the eruptions this area has experienced a great deal of faulting, fracturing, and erosion. Exposure of the varied volcanic rocks has created some impressive scenery.
In addition to the geology and scenery, there were also a number of interesting plants to be found. This chamise (Adenostoma fasciculatum, Rosaceae) had evergreen, needle-like leaves, but it’s not a conifer; it’s in the rose family.
The leaves of this manzanita (Arctostaphylos sp., Ericaceae) had turned pale in the winter, and they provided contrast against the red bark:
There were also quite a few mule deer (Odocoileus hemionus, Cervidae) in the lower elevations:
Although the weather wasn’t conducive to seeing California condors, there were a number of American crows (Corvus brachyrhynchos, Corvidae) soaring above the pinnacles:
The High Peaks Trail through Pinnacles National Monument provided a strenuous but exhilarating hike through some beautiful volcanic rocks in a chaparral environment. There are many more trails to hike here, as well as a variety of caves and other natural features. There are numerous reasons for me to return here, and I would especially love to catch a glimpse of the California condor, one of the rarest and largest flying birds on earth.
EDIT: As of January 11, 2013, Pinnacles is now a National Park.