Rough and Rugged! Welcome to Pinnacles!
Millions of years of volcanic activity along California's Coast Ranges has created the unusual
formations of Pinnacles National Monument, a park located near Soledad, California. The once
volcanic region today has been split in half from the transform fault running through the region known
as the San Andreas Fault. The split volcano, having last erupted 22 million years ago, is now found in
two locations: southern California and Pinnacles National Monument. The park is so rugged that
engineers could not build a single road to cross the park. Instead, Highway 146, accessible from US
101 or CA 25, retains its number on both roads that head into the park. For a short visit, it is best to
see West Pinnacles, where rock formations and caverns lure hundreds of visitors each month.
As California State Route 146 approaches the park, visitors
are greeted with this broad view of the pinnacle formations.
Large grassy areas often dry up in the summer heat, as
temperatures often reach 100 degrees. This view of the
pinnacle formations is from Route 146 just before it enters
park boundaries.
Route 146 slims down to nearly one lane as it enters a narrow
pass before dead-ending inside the park. Another portion  
branches off State Route 25 and heads west into the eastern
section of the park.
Unusual and jagged rock formations are typical of ancient
magmas that solidified underground before being exposed
millions of years later.
Geologists believe formations such as those found inside the
park were formed about 20 to 25 million years ago near
Lancaster, CA. Due to its position on the San Andreas Fault,
the formations were slowly moved to their present location,
and gradual erosion and weathering shaped the formations
visitors see today.  
Visitors pass through many wine-producing areas of the
Salinas Valley en route to Pinnacles National Monument.
Typical scene in Central California: cows grazing in a large
pasture that has dried by mid-summer.
California State Route 198 heads east from US 101 through
Green Valley. Note that the golden color of dried grasses, not
the famous Gold Rush, give California its nickname as the
"Golden State."