Composed of just over 16,000 acres, Pinnacles is located in the Gabilan Mountain Range on the east side of the Salinas Valley. The elevation ranges from near 800 ft on Chalone Creek to 3304 ft atop North Chalone Peak. The geologic formations that comprise the Pinnacles bear no resemblance to the surrounding smooth, round hills. Here you face rugged spires and crags that bear a passing semblance to Bryce Canyon in Utah. Unlike Bryce Canyon, these rocks are the remains of an ancient volcano. Or rather they are part of the remains, for the rest of this volcano lies 195 miles to the southeast in the Neenach formation near present day Lancaster, California. This occurred approximately 23 million years ago. As Pinnacles moved north on the Pacific Plate, two faults-the Chalone and the Pinnacle-lowered the rocks, protecting them from erosion. Later, these faults brought the volcanic remains back to the surface allowing erosion to create the formations you see today.
The monument has a variety of trails from easy to strenuous. Visitors come to the park for hiking, picnicking, and rock climbing. The majority of the hikers come to view the beautiful rock formations, abundant wildflowers and wildlife, and explore the caves.
Peak use time occurs during the spring (February through May). The summers can be quite hot with temperatures reaching over 100 degrees F. While the temperatures are more moderate in winter, rain discourages many visitors at this time of year.
Camping is limited in the park. There is a semi-primitive tent camp ground on the west side. For east side camping, a private camp ground operates 1/2 mile outside the park boundary, with showers and swimming pool available. There is no back country camping permitted in the monument.