 The transform fault, known as the San Andreas Fault was created during the Cenozoic Era by the movements of the Pacific Plate and North American Plate.The region experiences earthquakes and felt the shocks of the 2009 Gulf of California earthquake and 2010 Baja California earthquake.The main mountain ranges of the Peninsular Ranges ridging eastern San Diego–Tijuana are the Palomar Mountains, Laguna Mountains, Sierra de Juárez, and the peaks of the Cuyumacas including Cuyamaca Peak.