Natural Features & Ecosystems
Pinnacles National Park gets its name from rock spires and crags that are remnants of an ancient volcanic field, which eroded over millions of years as portions of the field moved northward along the San Andreas Fault. Rock debris in the form of boulders has weathered and settled, leaving behind spires of volcanic rock and talus caves.
Did You Know?
Pinnacles, Muir Woods, and the Grand Canyon were all set aside as national monuments in the span of seven days in January 1908 by Teddy Roosevelt.