Tranverse Ranges are mountains in Southern California with east-west trending.  Separated from the rest of the state by the Transverse Ranges, including the Tehachapi, which separate the Central Valley from the Mojave Desert, the Southern California mountains are often gentle and less prominent in the landscape, but sometimes can appear quite dynamic in places such as the San Bernardino mountains with the 11,499 foot-tall San Gorgonio peak. In the winter when it snows in the Southern California mountains at higher elevations, millions of beach residents are shocked to see the mountains that often are not visible, suddenly appear crested in white snow. Big Bear Lake is one such place that beckons people to go skiing, play hooky, or book a White Christmas in a cozy mountain cabin.

Urban Southern California intersperses the valleys between the Santa Susana Mountains, Santa Monica Mountains and San Gabriel Mountains, which range from the Pacific Coast, eastward over 100 miles, to the San Bernardino Mountains, north of San Bernardino.

The highest point of the range is Mount San Gorgonio at 11,499 feet.
 

The San Gabriel Mountains have Mount Wilson observatory.

The Transverse Ranges include a series of east–west trending mountain ranges that extend from Point Conception at the western tip of Santa Barbara County, eastward (and a bit south) to the east end of the San Jacinto Mountains in western Riverside County.

The Santa Ynez Mountains make up the westernmost ranges, extending from Point Conception to the Ventura River just west-northwest of Ojai, in Ventura County. Pine Mountain Ridge, Nordhoff Ridge–Topatopa Mountains, Rincon Peak–Red Mountain, Sulphur Mountain, Santa Paula Ridge, South Mountain–Oat Mountain–Santa Susana Mountains, Simi Hills, Conejo Mountains–Santa Monica Mountains are all part of the Western Transverse Ranges, in Ventura and western Los Angeles Counties.

The Liebre Mountains occupy the northwest corner of Los Angeles County, an extension of San Gabriel Mountains on the Pacific Plate side of the San Andreas Fault. The fault divides the San Gabriel Mountains from the San Bernardino Mountains further to the east in San Bernardino County.