When a crack formed in the crustal plate approximately 20 million years ago, the Peninsular Ranges Province and the San Jacinto Mountains rose at a relatively rapid rate.

The range-wide population of Peninsular bighorn was estimated at 1,171 in 1974, before declining to less than 300 adult sheep by 1996.

The range-wide population of Peninsular bighorn was estimated at 1,171 in 1974, before declining to less than 300 adult sheep by 1996.

Peninsular Ranges Batholith, Baja California and Southern California Douglas M. Morton and Fred K. Miller (editors) Geological Society of America Memoir 211 ...

The Eastern Peninsular Range, which includes the San Jacinto and Palomar mountains, are nearly 3,000 square miles. That would leave the two combined areas, ...

One of the most beautiful and fascinating flowers in the United States is the snow plant of California’s Sierra Nevada and peninsular ranges. Growing among melting snowbanks in shaded fir ...

Bighorn sheep in the Peninsular Ranges are currently listed as federally endangered. Project collaborators have determined that mountain lions are the primary threat to the bighorn sheep in the ...