Home to endangered black condors nesting in iconic volcanic
rocks, California's Pinnacles National Monument is set to become
America's newest national park. The park's spectacular pinnacles
are half of an eroded volcano. The matching half lies 195 miles
(314 kilometers) to the southeast, on the other side of the San
Andreas Fault. The 1976 discovery of the 23-million-year-old
split volcano provides a unique geologic marker of offset along
the fault. President Theodore Roosevelt established Pinnacles
National Monument in 1908, to preserve its massive monoliths and
wildlife. The giant spires are now a popular rock climbing
destination. Rounded knobs and pinnacles rise above Condor Gulch
in Pinnacles National Monument. Weathering of volcanic rock
gives rise to the park's unique landscape. Rhyolite cliffs near
the falls along the Condor Gulch Trail in Pinnacles National
Monument. Rhyolite is a volcanic rock similar to granite in
composition (mostly the minerals quartz and feldspar). A Landsat
satellite image of C