U.S. Route 101, orU.S. Highway 101 (US 101), is a major north–south highway that traverses the states of California, Oregon, and Washington on theWest Coast of the United States. It is part of theUnited States Numbered Highway System and runs for over 1,500 miles (2,400 km) along thePacific Ocean. The highway is also known by various names, includingEl Camino Real in parts of California, theOregon Coast Highway, and theOlympic Highway in Washington. Despite its three-digit number, normally used forspur routes, US 101 is classified as a primary route with 10 as its "first digit".
The highway is a major north–south link along thePacific 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 earlySpanish missions, pueblos, andpresidios. It originally terminated to the south inSan 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.
US 101 continues northwest intoSan Jose on the South Valley Freeway and later the Bayshore Freeway, which travels around the east and north sides of downtown San Jose. The ten-lane freeway generally follows the west side ofSan Francisco Bay as it traverses severalSilicon Valley communities, includingPalo Alto,Redwood City, andSan Mateo, and passes offices for high-tech companies.[25][26] It parallelsI-280, which travels along the foothills of theSanta Cruz Mountains to the west, as the two continue up theSan Francisco Peninsula.[27] US 101 passesSan Francisco International Airport and briefly turns northeast to rejoin the coastline before it enters the city of San Francisco nearCandlestick Point. The Bayshore Freeway intersects I-280 and terminates at an interchange withI-80 near theSoMa neighborhood in the city center.[21] US 101 then uses city streets to continue through San Francisco; it travels north onVan Ness Avenue, a wide boulevard withbus lanes, and west onLombard Street to thePresidio of San Francisco, a historic landmark and city park.[28][29]
Beyond the San Francisco Bay Area, US 101 is primarily an undivided highway with some short freeway sections and serves as the primary route in the ruggedNorth Coast region.[39] It traverses theMendocino Range and reaches the northern terminus of SR 1 atLeggett.[40] The Redwood Highway then follows theSouth Fork Eel River north intoHumboldt Redwoods State Park, where it runs parallel to theAvenue of the Giants.[41] US 101 continues northwest along theEel River to reach the coastline nearEureka, which it travels through on city streets before becoming a divided highway aroundHumboldt Bay. The highway travels north along the coast through theRedwood National and State Parks, where it passes through old-growthcoast redwood forests, and reachesCrescent City.[42] US 101 intersectsUS 199 north of the city and continues northwest along the coast to the Oregon state line.[21]
The Oregon Coast Highway begins at the California state line nearBrookings and carries US 101 north along the Pacific coast. It is generally a two-lane highway that passes through small towns and near 77state parks on the rugged coastline, as well as some inland areas.[43][44] From Brookings, US 101 traverses the 12-mile (19 km)Samuel H. Boardman State Scenic Corridor, which includes roadside viewpoints and trailheads that face the ocean.[45] The highway remains elevated from the coastline and briefly descends tosea level near thePistol River State Scenic Viewpoint before climbingCape Sebastian on its way toGold Beach. US 101 travels through Gold Beach and crosses theRogue River to continue north along the coast.[21] The highway turns west to follow the base ofHumbug Mountain, a 1,761-foot (537 m) mountain that rises from the Pacific Ocean,[46] and northwest to reachPort Orford, where it leaves the coastline.[47][48]
The Oregon Coast Highway crosses theSiuslaw River intoFlorence and intersectsOregon Route 126 (OR 126), a major east–west route that traverses theCoast Range toEugene.[47] US 101 returns to the coastline near theHeceta Head Lighthouse and continues north along several high cliffs aroundCape Perpetua andYachats that overlook the beaches.[53][54] The Oregon Coast Highway then crosses theYaquina Bay Bridge intoNewport and serves as the western terminus ofUS 20, a transcontinental route toBoston and the longest highway in the United States.[55] US 101 continues along the coastline andSiletz Bay intoLincoln City, where it serves as the city's main street for 7 miles (11 km)[56] and turns away from the coast to bypass theCascade Head biosphere reserve.[57][58] The highway briefly returns to the coastline before beginning a long inland stretch that follows theNestucca River and other streams toTillamook.[21][59]
US 101 enters Washington state at the north end of the Astoria–Megler Bridge and immediately turns west to follow the Columbia River. The highway traversesFort Columbia State Park in a tunnel and passes throughChinook on the north side of the river's mouth towardsIlwaco, nearCape Disappointment.[62] From Ilwaco, US 101 briefly travels north before turning east atSeaview, the southernmost city on theLong Beach Peninsula,[63] and followingWillapa Bay to a junction withState Route 4 (SR 4) on theNaselle River.[64] The highway continues along the east side of the bay throughSouth Bend toRaymond, where it travels inland to cross the forestedWillapa Hills to reachAberdeen. US 101 enters the city by crossing theChehalis River and turns west onto a pair of one-way streets after an intersection withUS 12.[21][65]
The streets travel through western Aberdeen and neighboringHoquiam, where the highway is split by theHoquiam River, and rejoin north of downtown. The highway continues north along inland streams into theQuinault Indian Reservation, which it enters nearLake Quinault at the edge ofOlympic National Park.[66] US 101 circumnavigates theOlympic Peninsula and provides the main access to the national park and various sites via spur roads;[67] there are no roads that cross theOlympic Mountains, which separate areas of the national park and adjacentOlympic National Forest.[66][68] The highway turns west from Lake Quinault to reach the Pacific coastline, which it follows for 15 miles (24 km) betweenQueets andRuby Beach within Olympic National Park.[69] US 101 then heads northeast to follow theHoh River upstream and intersects the main access road to theHoh Rainforest.[70] It then travels north throughForks and follows theSol Duc River east to re-enter the national park.[21][66]
The highway travels south and crosses apass in the Olympic Mountains nearMount Walker before it reaches the west shore ofHood Canal, which it follows for more than 50 miles (80 km).[70][74] US 101 passes severalstate parks and additional access points for the national park, includingLake Cushman nearHoodsport.[66] It leaves Hood Canal on theSkokomish Indian Reservation and continues south on a super two bypass aroundShelton, where it intersectsSR 3. US 101 then becomes a freeway and cuts across several inlets and bays ofPuget Sound as it turns southeast towards the Olympia area.[75] The freeway merges withSR 8 and continues southeast to reach its northern terminus at I-5 inTumwater,[5] near theWashington State Capitol campus in nearby Olympia.[21][65]
The section between Lake Crescent and Sequim is generallysigned east–west,[3] while the section south of the intersection with SR 20 is signed north–south but turned 180 degrees.[5] The direct route between Aberdeen and Olympia uses US 12 and SR 8, which complete the Olympic Loop Highway.[65]
According to theAmerican Association of State Highway and Transportation Officials's (AASHTO) numbering scheme forUnited States Numbered Highways, three-digit route numbers are generally subsidiaries of two-digit primary routes. Of these two-digit routes, the principal north–south routes were assigned numbers ending in 1.[76][77] US 101 is an exception to the three-digit rule due to its role as the westernmost major route;[78] it is treated as a primary, two-digit route with a "first digit" of 10, rather than a spur ofUS 1, which is located along the east coast.[76][79]
US 101 was established as part of the initial United States Numbered Highway System that was developed by theAmerican Association of State Highway Officials (AASHO) in the 1920s. The preliminary plan recommended in 1925 had the highway terminate atSan Diego in the south and inPort Angeles, Washington, to the north.[80][81] The final plan extended US 101 within Washington around the east side of the Olympic Peninsula to Olympia[82] and was adopted by the AASHO on November 11, 1926.[4][83] The first section of US 101 to be signed in California was between San Diego and Los Angeles in January 1928, which was followed by the rest of the route later in the year.[84]
Portions of the coastal highway had already been constructed by the respective state governments and also followed foot and wagon routes developed in earlier centuries.[85] Among these wasEl Camino Real in California, which was formed by thePortolá expedition in 1769 and 1770 and connected the historicSpanish missions, pueblos, andpresidios.[86][87] The California state government chose a section of El Camino Real in San Bruno in 1912 to become the first paved highway in the state.[88][89] The San Diego–San Francisco section of El Camino Real was incorporated into the multi-statePacific Highway in the 1910s;[90][91] other sections of US 101 in California used the existing Redwood Highway, which was constructed from 1917 to 1923,[92] and Coast Highway.[93]
A section of the Oregon Coast Highway nearHumbug Mountain, photographed in 1938
Construction of the Oregon Coast Highway began in 1921, two years after a statereferendum that voted in favor of funding the development of highways with a one-centgas tax. At the time, several short wagon roads and plank roads connected settlements on the coast, and overland travel primarily used beaches.[94][95] The highway was gradually constructed and paved in the 1920s, but a set of sixferry crossings remained. These ferries were operated by private companies until the state government acquired them in 1927 with plans to replace them with bridges.[96] The five major Oregon bridges on US 101 were designed by state engineerConde B. McCullough and opened by 1936 using funding from the federal government'sNew Deal programs. As automobile traffic on the Oregon Coast increased, other sections were realigned to avoid rugged terrain or bypassed with tunnels.[97] The Oregon Coast Highway was declared complete on October 3, 1936, and cost $25 million to construct (equivalent to $443 million in 2024 dollars).[98][99]
Washington completed the final sections of the Olympic Loop Highway between 1927 and 1931 for $11 million (equivalent to $182 million in 2024 dollars).[99][100] The project paved several existing sections of the state roads and also constructed 7 miles (11 km) of new highway from theQueets River to Ruby Beach nearKalaloch. Portions of US 101 passed through lands that were later incorporated into Olympic National Park when it was established in 1938; under theNational Park Service, sections of the Crescent Lake Highway were widened and improved in 1949.[101] TheWashington State Highway Commission submitted an application to AASHO in 1955 to extend US 101 northeast from Discovery Bay toWhidbey Island andMount Vernon, where it would terminate atUS 99.[102] The proposal was rejected by AASHO for being too long of a detour and including a tolled ferry crossing.[103]
US 101 was split into two routes in the San Francisco Bay Area between San Jose and San Francisco in 1929:[104] US 101W followed El Camino Real on the San Francisco Peninsula for 50 miles (80 km); US 101E traversed theEast Bay for 54 miles (87 km) toOakland, where it turned west on across-bay ferry to San Francisco.[105][106] The branches converged in Downtown San Francisco and traveled along city streets to theHyde Street Pier, where the highway continued on automobile ferries toSausalito at the south end of the Redwood Highway.[107] By 1936, US 101E had been eliminated in favor of the route on the west side, which was re-designated as US 101.[108]
The Hyde Street–Sausalito ferry was removed from US 101 following the May 1937 completion of theGolden Gate Bridge, which would carry the highway from San Francisco to Marin County.[109][110] It was thelongest suspension bridge in the world at the time of its construction and was funded by a $35 million regionalbond (equivalent to $598 million in 2024 dollars)[99] that was paid off in 1971.[111][112] The San Jose–San Francisco section of US 101 was initially moved from El Camino Real to theBayshore Highway,[113] a four-lane undivided highway that was constructed between 1924 and 1937 to bypass several towns on the peninsula.[114][115] El Camino Real was re-designated as US 101 Alternate in 1936,[116] which sparked outcry from businesses and groups who lobbied for a reversal of the change that was submitted by state officials to AASHO.[117][118] In 1938, US 101 was moved back to El Camino Real and the Bayshore Highway was designated as US 101 Bypass.[119][120]
In the late 1940s, the California state government announced plans to convert most of US 101 between Los Angeles and San Francisco to freeways using funds from theCollier–Burns Highway Act of 1947.[121][122] Prior to the act, the Cahuenga Pass Freeway had opened in June 1940 between Hollywood and the San Fernando Valley in Los Angeles to replace a narrow, winding mountain road. It was the city's second freeway and was later extended southeast towards Downtown and renamed the Hollywood Freeway when it was completed on April 16, 1954.[20] Several other early freeway segments were signed as US 101 Bypass or US 101 Alternate.[123] InSan Luis Obispo, a freeway around the northwest side of downtown was completed by the early 1960s, alongside bypasses of nearby rural towns.[124] The San Diego–San Francisco section of US 101 was designated as El Camino Real by the California state government in 1959 as part of a program to add historic markers on the highway.[125]
TheSanta Ana Freeway was planned as a Los Angeles–Irvine connector in the late 1930s and constructed in phases, beginning with a section near Downtown Los Angeles that opened in December 1947.[126][127] US 101 was later moved onto sections of the freeway, which was completed in 1958 and served as a continuation of the Hollywood Freeway.[128][129] By the time it was completed, sections of the freeway between Anaheim and Los Angeles were carrying over 113,000 vehicles per day and were planned to be widened to six lanes within a few years.[130][131] The south end of the Santa Ana Freeway merged into theSan Diego Freeway, which began construction in 1954 and was completed in 1968.[132][133] Both freeways were incorporated into plans for the newInterstate Highway System in 1955 and assigned to I-5 three years later.[134][135]
US 101 was truncated to Los Angeles during a 1963 AASHO meeting at the request of the California state government, as I-5 had replaced the stretch to San Diego;[85][136] the changes were made ahead of amajor restructuring of the state's highway system that took effect on July 1, 1964.[137] The old sections of the highway from San Diego to Los Angeles were given local names and later signed as Historic US 101 in the late 2010s by local governments.[85] The 1963 action also moved the San Jose–San Francisco section onto theBayshore Freeway,[136] which was built to replace the Bayshore Highway on US 101 Bypass.[138] The freeway had been proposed to address congestion and frequent collisions on the highway, nicknamed "Bloody Bayshore", and opened in stages between 1947 and 1962.[115][138] The bypassed sections of El Camino Real were renumbered toSR 82 in the Bay Area and signed as business routes of US 101 in other cities.[139][140] From the north end of the Bayshore Freeway atI-80 in San Francisco, US 101 was routed west along a section of theCentral Freeway, which opened in 1955 and was extended four years later to Van Ness Avenue.[141][142] Plans to extend the Central Freeway and other thoroughfares through San Francisco to the Golden Gate Bridge were later cancelled by the mid-1960s followingwidespread opposition and protests from city residents.[143][144]
Several sections of the Oregon Coast Highway were rebuilt in the 1950s and 1960s to eliminate curves and move the highway further from the coastline in cities such as Cannon Beach.[145] A 53-mile (85 km) realignment from Brookings to Gold Beach and a more direct route from Bandon to Coos Bay to bypassCoquille were completed as part of this program in the early 1960s.[146][147] In 1955, Oregon congressmanA. Walter Norblad unsuccessfully proposed that the US 101 corridor be included in theInterstate Highway System to allow for federal funds to construct a bridge across the Columbia River;[148] the proposal was also endorsed by aU.S. Army official, who also sought a similar designation for the Washington section.[149] The Seaside–Astoria section was straightened and realigned onto anew bridge over Youngs Bay in 1964.[150] TheAstoria–Megler Bridge over the Columbia River opened to traffic on July 29, 1966, replacing a ferry and comprising the final "link" in US 101.[61][151] The northern terminus of US 101 was originally at Capitol Way (US 99) in downtown Olympia until it was moved to a freeway bypass in December 1958.[152][153] The freeway section was extended northwest from Olympia toShelton in 1965.[154]
The final traffic signal on the 435-mile (700 km) section of US 101 between Los Angeles and San Francisco, located at Anacapa Street in Santa Barbara, was removed in November 1991.[155] The removal was spurred by the construction of a freeway through Santa Barbara, which was completed the following year and bypassed four signalized intersections.[156] The Central Freeway's northernmost leg in San Francisco was demolished in the early 2000s after it had sustained damage in the1989 Loma Prieta earthquake, which required the upper deck to be removed in 1997.[157] A portion of the corridor was replaced byOctavia Boulevard, which opened in 2005, while US 101 was rerouted onto Van Ness Avenue further east.[21][158] From 2016 to 2022, Van Ness Avenue was rebuilt by theSan Francisco Municipal Railway to add center bus lanes and landscaped medians as part of theVan Ness Bus Rapid Transit project.[159]
Several existing freeway sections in California were expanded to addhigh-occupancy vehicle lanes (HOV lanes) beginning in the 1980s to address increased congestion, especially in the San Francisco Bay Area.[160][161] By 1984, a section in Marin County had been opened to traffic;[162] it was followed by sections in San Mateo and Santa Clara counties that were funded by a sales tax approved in a 1984 ballot measure.[163] The HOV lanes were extended south through San Jose to Bernal Road in 1990.[164] A 16-mile (26 km) section of the existing HOV lanes fromRedwood City toSan Bruno was converted tohigh-occupancy toll lanes in 2023 with the use ofelectronic toll collection.[165][166]
Sections of US 101 in Oregon have been rebuilt or relocated due to erosion or landslides that caused considerable damage to the highway.[7][167] The use ofriprap to reinforce new sections of the roadway was banned by theOregon Department of Land Conservation and Development in 1977 due to its effect on beach degradation. An effort to repeal the ban and rebuild sections of US 101 began in 2002 and resulted in an amendment in 2022.[7][168] Several sections of US 101 between Newport and Lincoln City are identified as persistent sunken grade and rockfall areas in need of frequent repairs.[168] Other portions of the highway in southwestern Oregon had landslide and subsidence issues, including a section inHarbor that was closed for several weeks in early 2016 by an 80-foot (24 m)sinkhole.[169][170]
Severe erosion of the highway along theHoh River in Washington was addressed through the construction of eight engineeredlogjams by theWashington State Department of Transportation in 2004. The project redirected the river's flow through the use of dense piles ofspruce logs reinforced by steel piles; the highway previously underwent four emergency repairs in the area that included installation of riprap and other conventional materials.[171][172] US 101 was relocated onto an expressway bypass ofSequim, Washington, in August 1999 that replaced a congested route on the city's main street, Washington Avenue. The 4.4-mile (7.1 km) project cost $40.7 million (equivalent to $71.8 million in 2024 dollars)[99] to construct and included the installation ofwarning signals triggered by the presence of nearbyRoosevelt elk wearingradio collars for tracking.[173][174] The 15-mile (24 km) section of the highway between Port Angeles and Sequim was widened to four lanes in November 2014 following a two-year project to fill the final, 3.5-mile (5.6 km) gap.[175] The 12-mile (19 km) section west of Port Angeles along Lake Crescent was rehabilitated from 2017 to 2019 to repave the roadway and repair structures—among them retaining walls and guardrails.[176]
A six-mile (9.7 km) freeway bypass ofWillits, California, for the Redwood Highway opened in November 2016 at a cost of $460 million (equivalent to $593 million in 2024 dollars).[99][177] The bypass was expected to divert away tourists and cause a drop in localsales tax revenue due to lost traffic.[178] A portion of US 101 in the North Bay region near San Francisco, nicknamed the "Novato Narrows", was widened to three lanes with the addition of an HOV lane; construction on the 5-mile (8.0 km) section began in 2011 and is scheduled to be completed in 2026.[179] A four-phase widening through the Santa Barbara area to add a third lane in each direction began construction in 2008. Its final phase is estimated to cost $700 million and be completed in 2027.[180][181] The world's largest urbanwildlife crossing, named theWallis Annenberg Wildlife Crossing, is under construction over US 101 inAgoura Hills, California, and is scheduled to open in 2025.[182]
^Total length is calculated from route mileage within California (806.597 miles, 1,298.092 km),[1] Oregon (363.11 miles, 584.37 km),[2] and Washington (365.53 miles, 588.26 km).[3]
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^"2-mile freeway section to open".The Seattle Times. July 19, 1965. p. 21.
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I-5 /I-10 inLos Angeles, CA
.jpg)
SR 110 toI-110 in Los Angeles
SR 134 /SR 170 in Los Angeles
I-405 in Los Angeles
I-280 /I-680 inSan Jose
I-880 in San Jose
SR 92 in San Mateo
I-380 on theSan Bruno–South San Francisco city line
I-80 in San Francisco
SR 1 in San Francisco
I-580 inSan Rafael
US 199 nearCrescent City
OR 38 inReedsport
OR 126 inFlorence
US 20 inNewport
OR 22 atHebo
US 26 nearCannon Beach
US 30 inAstoria
US 101 Alt. nearIlwaco
SR 4 nearNaselle
US 12 inAberdeen
SR 20 atDiscovery Bay
SR 3 nearShelton
SR 8 nearOlympia
