The Cerro Prieto Fault is a right-lateral strike-slip fault in the Mexicali Valley of Baja California, forming a key link in the plate boundary that connects the San Andreas system to the spreading centres of the Gulf of California. Here the Pacific and North American plates slide past one another as the Gulf slowly pulls Baja California away from mainland Mexico.
The fault marks a transform segment between two extensional basins, and it is associated with the Cerro Prieto geothermal field, one of the largest in the world, where heat rising along the plate boundary is tapped for electricity. Its slip rate is high for a continental fault, on the order of several centimetres per year.
The region is highly active, and the fault is closely linked to the 2010 El Mayor-Cucapah earthquake (magnitude 7.2), which struck just to the south, damaged Mexicali and Calexico and was felt across southern California. Repeated moderate-to-large quakes along this boundary make the Mexicali Valley one of Mexico's most seismically hazardous zones.