Lancaster is the eighth-largest city in Los Angeles County and the 9th fastest growing city in the United States. Lancaster is located approximately 70 miles (112.5 km) north (by road travel) of the city of Los Angeles in Southern California's Antelope Valley. It is separated from the Los Angeles Basin by the San Gabriel Mountain Range to the south and from Bakersfield and the San Joaquin Valley by the Tehachapi Mountain Range to the north.