Patagonia Mountains the Sonoran town of San Lazaro. The old mining camps and ghost towns of Mowry, Washington Camp, Harshaw, and Duquesne are located in the Patagonia Mountains. Nogales, Arizona, and Nogales, Sonora, are in the valley to the southwest of the mountain range. The San Rafael Valley and Canelo Hills are to the east of the Patagonia Mountains. The connected Santa Rita, Patagonia, and Sierra San Antonio ranges are part of the Madrean Sky Islands ecoregion, the sky island mountain ranges region on the north of the Sierra Madre Occidental, the major cordillera and mountain ecoregion of central-western and northwestern Mexico.
Peninsular Ranges Francisco, Sierra de la Giganta, and Sierra de la Laguna in Baja California. Palomar Mountain, home to Palomar Observatory, is in the Peninsular Ranges in San Diego County, as is Viejas Mountain and the San Ysidro Mountains. The Peninsular ranges run predominantly north-south, unlike the Transverse Ranges to their north, which mostly run east-west. 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