San Gorgonio Mountain, also known locally as Mount San Gorgonio, or Old Greyback, is the highest peak in Southern California and the Transverse Ranges at 11,503 feet. It is in the San Bernardino Mountains, 27 miles east of the city of San Bernardino and 12 miles north-northeast of San Gorgonio Pass. It lies within the San Gorgonio Wilderness, part of the Sand to Snow National Monument managed by the San Bernardino National Forest.