High Quality Content by WIKIPEDIA articles! U.S. Route 101, or U.S. Highway 101, is an important north–south U.S. highway that runs through the states of California, Oregon, and Washington, on the West Coast of the United States. It is also known as El Camino Real (The Royal Road) where its route along the southern and central California coast approximates the old trail which linked the Spanish missions, pueblos, and presidios. It merges at some points with California Highway 1.