Route 66 in California crosses the state from the Colorado River near Needles, running with a westwards course through the rugged terrain of the Mojave Desert, reaching Barstow where it ran south near the Mojave River to Victorville and then climbing the gap between the San Gabriel and San Bernardino Mountains, crossing San Andreas Fault and reaching San Bernardino.
Here it runs west along the foothills of the San Gabriel Mountains across San Gabriel Valley in the suburbs of Los Angeles and in Pasadena it heads into the downtown district, and then across Hollywood and Beverly Hills to its western terminus on the Pacific Ocean's coast in Santa Monica.