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 Washington
U.S. Route 101 Alternate is a 0.61-mile (0.98 km) bypass of Ilwaco. US 101 Alt. opened in 1931 as a branch of PSH 12, the early designation of the southern section of US 101 through Washington. The highway was not fully recognized by the AASHTO until October 2006, even though many maps from the 1930s state that it is part of the U.S. Route system.