The first 2,500 acres of the rugged Pinnacles were made a national monument in 1908 by President Theodore Roosevelt. Since 1908, the monument significantly increased in size to 26,000 acres and in 2013, President Barack Obama designated the expansive terrain as a national park. The park's namesakes are the eroded leftovers of the western half of an extinct volcano that has moved 150 miles (240 km) from its original location on the San Andreas Fault. The rock formations are made of Rhyolite breccia that is composed of lava sand, ash, and angular chunks of rock that were explosively ejected from the Pinnacles Volcano and provide for spectacular pinnacles that attract rock climbers. The park features unusual talus caves that house at least thirteen species of bat.
It was so fun to walk through the dark caves on Bear Gulch Cave Trail and enjoy the beautiful view at the Reservoir while soaking up some sun. Touching the smooth bark of the Manzanita trees, talking with friends as we go, kids exclaiming how incredible this place is... Days like this remind us that this is why we do what we do!