When the Pacific Plate collided with (and wrenched off a portion of) the North American plate, the San Andreas Rift Zone was created. A potential haven for volcanoes, this created the original Pinnacles formation (Neenach) 23 million years ago. As the Pacific plate inched up North, a part of the Pinnacles moved along with it, and today it lies 195 miles north of its original location.
Pinnacles National Monument is a decent place for a day hike, only two hours from the San Francisco Bay area. My path let me explore all geologic aspects of this Monument: I started off from the Chaparral end and took the Juniper Canyon Trail (1.2 miles), took a left onto the Tunnel Trail (0.6 miles). This was a fairly strenous portion of the hike and it let enjoy some cool views: .
At the intersection of the High Peaks and Tunnel trails, I took a left to explore a bit of the High Peaks trail and then walked back to the intersection (2 miles total). Along this region of the trail, I was able to see a Condor's nest and got some excellent footage of these graceful birds in flight . Parts of this trail involve steep climbs on steps carved out of rock . Again, this presented some excellent views: .
I then took the High Peaks Trail all the way to Chalone Creek (2.6 miles) where I got to see the Pinnacles and took a leisurely walk along the valley on Old Pinnacles Trail (2.3 miles) all the way to the Balconies Caves (0.4 miles) .
Navigating the caves in the dark is a lot of fun, particularly if you're completely alone. At points, there is absolute no light and all you have is a flashlight that you need to use to follow the "trail" and watch for huge boulders that hang from the ceiling. Sometimes you have to squeeze real hard to get through certain areas.
After I climbed out from the caves, I turned right back (0.4 mile) and went along the Balconies Cliffs (0.8 miles) as the sun was setting and headed back to Chaparral (0.6 miles). Total trip: 10.9 miles.