U.S. Route 101

U.S. Route 101
US 101 highlighted in red
Route information
Length	1,535.27 mi[a] (2,470.78 km)
Existed	November 11, 1926 (1926-11-11)[4]–present
Major junctions
South end	I-5 / I-10 / SR 60 in Los Angeles, CA
Major intersections	I-80 in San Francisco, CA US 199 near Crescent City, CA US 20 in Newport, OR US 26 near Seaside, OR US 30 in Astoria, OR US 12 in Aberdeen, WA
North end	I-5 in Tumwater, WA
Location
Country	United States
States	California, Oregon, Washington
Highway system
United States Numbered Highway System List Special Divided
← US 99 → US 163

U.S. Route 101, or U.S. Highway 101 (US 101), is a north–south highway that traverses the states of California, Oregon, and Washington on the West Coast of the United States. It is part of the United States Numbered Highway System and runs for over 1,500 miles (2,400 km) along the Pacific Ocean. The highway is also known by various names, including El Camino Real in parts of California, the Oregon Coast Highway, and the Olympic Highway in Washington. Despite its three-digit number, normally used for spur routes, US 101 is classified as a primary route.

The highway's southern terminus is at a major interchange with Interstate 5 (I-5) and I-10 in Los Angeles. US 101 follows several freeways in Southern California as it travels north of the Santa Monica Mountains and along the coast, where it is concurrent with California State Route 1 (SR 1). The highway travels inland from the coast after it splits from SR 1 and approaches the San Francisco Bay Area, where it becomes the Bayshore Freeway and later traverses San Francisco on city streets to reach the Golden Gate Bridge. US 101 continues north on the Redwood Highway and rejoins the coast before it enters Oregon.

The Oregon Coast Highway carries US 101 through the state's coastal towns and regions in the foothills of the Oregon Coast Range. The highway crosses over the Columbia River on the Astoria–Megler Bridge into Washington, where it follows Willapa Bay and an inland route to Aberdeen and Olympic National Park. US 101 travels north and east around the Olympic Peninsula and reaches its northernmost point in Port Angeles; from there, it travels east and later south to its northern terminus at I-5 in Tumwater, near Olympia. Several portions of the highway are also designated as scenic byways, including the Pacific Coast Scenic Byway in Washington; US 101 also serves three national parks: Pinnacles, Redwood, and Olympic.

The highway is a major north–south link along the Pacific coast north of San Francisco but does not serve the largest cities in Oregon and Washington; that role is instead filled by I-5, which has a more direct inland routing. US 101 was established in 1926 and followed several historic routes, including El Camino Real, which linked California's early Spanish missions, pueblos, and presidios. It originally terminated to the south in San Diego but was truncated to Los Angeles in 1964 after the construction of I-5. Other sections were later moved to freeway alignments that bypassed cities. Several sections of US 101 in Washington and Oregon were rebuilt in the mid-20th century to eliminate curves and address traffic congestion. Later projects expanded the Bayshore Freeway in the San Francisco Bay Area and relocated sections of the highway in Oregon in response to landslides and erosion.

Cite error: There are <ref group=lower-alpha> tags or {{efn}} templates on this page, but the references will not show without a {{reflist|group=lower-alpha}} template or {{notelist}} template (see the help page).