Peninsular Ranges

The Peninsular Ranges (also called the Lower California province) are a group of mountain ranges, in the Pacific Coast Ranges, which stretch 1,500 km (930 mi) from southern California in the United States to the southern tip of Mexico's Baja California Peninsula; they are part of the North American Coast Ranges that run along the Pacific coast from Alaska to Mexico. Elevations range from 500 to 11,500 feet (150 to 3,510 m).

Geography

The Peninsular Ranges include the Santa Ana, Temescal Mountains and other mountains and ranges of the Perris Block, San Jacinto and Laguna ranges of southern California with the Sierra de Juarez, Sierra San Pedro Mártir, Sierra de la Giganta, and Sierra de la Laguna of Baja California. Palomar Mountain, home to Palomar Observatory, is in the Peninsular Ranges in San Diego County, as is Viejas Mountain. The Peninsular ranges run predominantly north-south, unlike the Transverse Ranges to their north, which mostly run east-west.

Geology

Rocks in the ranges are dominated by Mesozoic granitic rocks, derived from the same massive batholith which forms the core of the Sierra Nevada Mountains in California. They are part of a geologic province known as the Salinian Block which broke off the North American Plate as the San Andreas Fault and Gulf of California came into being.