U.S. Route 101
The nearly highway's northern terminus is in Tumwater, Washington: the route remains along the Olympic Peninsula's coastal perimeter west, north, and east; the northernmost point on the highway is in Port Angeles. The southern terminus of US 101 is in Los Angeles at the East Los Angeles Interchange, the world's busiest freeway interchange.
U.S. Route 101
In Southern California, the highway is a heavily traveled commuter route serving the Northwest portion of the Greater Los Angeles area; this includes Ventura County communities in the West Conejo Valley and in the Oxnard Plain, along with Los Angeles County communities in the East Conejo Valley and San Fernando Valley. The route is the Santa Ana Freeway from East Los Angeles to Downtown Los Angeles. It becomes the Hollywood Freeway north of Downtown Los Angeles through the Cahuenga Pass, before turning west and becoming the Ventura Freeway. Communities along the alignment include Hollywood and the southern edge of the San Fernando Valley, and the cities of Hidden Hills, Calabasas, Agoura Hills, Westlake Village, Thousand Oaks (includes Newbury Park), Camarillo, Oxnard, Ventura, Santa Barbara, Santa Maria, San Luis Obispo and Atascadero.
In Northern California, US 101 is the primary coastal route providing motorists access in and out of the San Francisco Bay Area, as well as the primary commuter route between San Francisco and the North Bay. It is one of two major freeway routes connecting the South Bay and Silicon Valley with San Francisco and the North Bay. It serves as a more urban alternative to the rural I-280, as US 101 runs through Peninsula cities closer to the Bay, while I-280 runs closer to the Santa Cruz Mountains and Skyline Boulevard. Through northern San Francisco, US 101 remains routed on congested city streets due to freeway revolts, leaving the city on the iconic Golden Gate Bridge. It then departs the immediate coast and continues through wine country and Redwood forests until it re-emerges coast-side at Eureka. The route provides access through the extraordinarily rugged and scenic terrain of the North Coast and into vast groves of protected Redwoods in area parks, including Redwood National and State Parks before reaching the Oregon border.