The San Gabriel Mountains (Spanish: Sierra de San Gabriel) are a mountain range located in northern Los Angeles County and western San Bernardino County, California, United States. The mountain range is part of the Transverse Ranges and lies between the Los Angeles Basin and the Mojave Desert, with Interstate 5 to the west and Interstate 15 to the east. The range lies in, and is surrounded by, the Angeles and San Bernardino National Forests, with the San Andreas Fault as its northern border.