Multnomah County /mʌltˈnoʊmə/ is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the county's population was 815,428. Multnomah County is part of the Portland–Vancouver–Hillsboro, OR–WA metropolitan statistical area. Though smallest in area, Multnomah County is the state's most populous county. Its county seat, Portland, is the state's largest city.
 The area of the lower Willamette River has been inhabited for thousands of years, including by the Multnomah band of Chinookan peoples long before European contact, as evidenced by the nearby Cathlapotle village, just downstream.
 Multnomah County (the 13th in Oregon Territory) was created on December 22, 1854, formed out of two other Oregon counties – the eastern part of Washington County and the northern part of Clackamas County. Its creation was a result of a petition earlier that year by businessmen in Portland complaining of the inconvenient location of the Washington County seat in Hillsboro and of the share of Portland tax revenues leaving the city to support Washington County farmers. County commissioners met for the first time on January 17, 1855.
 The county is named after the Chinookan word for the "lower river", multnomah, matlnomaq, or máɬnumax̣ being interpretive English spellings of the same word. In Chinook jargon, Ne-matlnomaq, means the "place of matlnomaq" or the (singular) Ne-matlnomag, "the lower river", from the Oregon City Falls toward the Columbia River. Alternatively, Chinookan máɬnumax̣ (also nímaɬnumax̣) "those toward water" (or "toward the Columbia River", known in Chinookan as ímaɬ or wímaɬ, "the great water"). Explorer William Clark wrote in his journal: "I entered this river...called Multnomah...from a nation who reside on Wappato Island, a little below the enterence" (quoted from Willamette Landings by H.M. Corning).(see:Portland Basin Chinookan Villages in the early 1800s, Boyd and Zenk,) Although Clark refers to the Willamette River as Multnomah, he may not have understood the meaning. Simply put, Multnomah ("down river" or "toward the great water") is the shortened form of nematlnomaq/nímaɬnumax̣.
 In 1924, the county's three commissioners were indicted and recalled by voters "in response to 'gross irregularities' in the award of contracts for construction of the Burnside and Ross Island bridges"; since all three had been supported by the Ku Klux Klan, their recall also helped reduce that organization's influence in the city.
 Vanport, built north of Portland in 1943 to house workers for Kaiser Shipyards, was destroyed by a flood five years later.
 In 1968, the Oregon Legislative Assembly referred a bill, Ballot Measure 5, to voters that would amend the state constitution to allow for consolidated city-county governments when their populations are over 300,000. The 1968 voters' pamphlet noted that Multnomah County would be the only county in Oregon affected by the measure and voters approved the referendum in the 1968 general election. Since the approval of Measure 5 in 1968, an initiative to merge the county with Portland  has been considered and placed on the county ballot several times.
 In the 2000 presidential election, Multnomah county played a decisive role in determining the winner of the state's electoral votes. Al Gore carried the county by 104,764 votes, enough to offset the 97,999 vote advantage that George W. Bush had earned among Oregon's 35 other counties. The Democratic tilt was repeated in 2004, when John Kerry won by 161,146 votes, and in 2008, when Barack Obama won by 204,525 votes.
 In February 2001, the Multnomah County Board of Commissioners unanimously accepted the recommendation of the Library Advisory Board and authorized the library to enter into a lawsuit to stop the Children's Internet Protection Act.  The US Supreme Court ultimately decided in 2003 that the law was constitutional in US v. ALA. However, the library chose to turn down $104,000 per year of federal funding under CIPA to be able to continue to offer unfiltered Internet access.
 Faced with decreasing government revenues due to a recession in the local economy, voters approved a three-year local income tax (Measure 26–48)  on May 20, 2003, to prevent further cuts in schools, police protection, and social services. Multnomah County was one of the few local governments in Oregon to approve such a tax increase.[citation needed]
 On March 2, 2004, Multnomah County Chair Diane Linn announced the county would begin granting licenses for same-sex marriages, pursuant to a legal opinion issued by its attorney deeming such marriages lawful under Oregon law. Her announcement was supported by three other commissioners (Serena Cruz, Lisa Naito, and Maria Rojo de Steffey), but criticized by Lonnie Roberts, who represents the eastern part of Multnomah County and was left out of the decision.[failed verification] Within a few days, several groups joined to file a lawsuit to halt the county's action.[citation needed]
 After that, though, Linn and the three commissioners developed a public feud, with the latter becoming known as the "mean girls".  The county government has also faced significant budget issues, including not being able to open the Wapato Corrections Facility since it was built in 2003.
 According to the United States Census Bureau, the county has a total area of 466 square miles (1,210 km2), of which 34 square miles (88 km2) (7.4%) are covered by water. It is the smallest county in Oregon by area. It is located along the south side of the Columbia River.
 The county includes a number of extinct volcanoes in the Boring Lava Field. The Oregon side of the Columbia River Gorge forms the eastern portion of the county's northern border.
 As of the census of 2020, there were 815,428 people residing in the county.
 As of the census of 2010, 735,334 people, 304,540 households, and 163,539 families resided in the county. The population density was 1,704.9 inhabitants per square mile (658.3/km2). There were 324,832 housing units at an average density of 753.2 units per square mile (290.8 units/km2). The racial makeup of the county was 76.5% White, 6.5% Asian, 5.6% Black or African American, 1.1% American Indian, 0.5% Pacific Islander, 5.1% from other races, and 4.6% from two or more races. Those of Hispanic or Latino origin made up 10.9% of the population. In terms of ancestry, 19.4% were German, 12.2% were Irish, 11.4% were English, and 4.2% were American.
 Of the 304,540 households, 27.0% had children under 18 living with them, 38.6% were married couples living together, 10.7% had a female householder with no husband present, 46.3% were not families, and 32.6% of all households were made up of individuals. The average household size was 2.35 and the average family size was 3.03. The median age was 35.7 years.
 The median income for a household in the county was $49,618 and for a family was $62,956. Males had a median income of $45,152 versus $38,211 for females. The per capita income for the county was $28,883. About 11.3% of families and 16.0% of the population were below the poverty line, including 21.1% of those under age 18 and 12.1% of those age 65 or over.
 As of the census of 2000, 660,486 people lived in the county, organized into 272,098 households and 152,102 families. The population density was 1,518/sq mi (586/km2). The 288,561 housing units had an average density of 663.sq mi (256/km2). The racial makeup of the county was 79.16% White, 5.70% Asian, 5.67% Black or African American, 1.03% Native American, 0.35% Pacific Islander, 4.03% from other races, and 4.07% from two or more races. About 7.51% of the population were Hispanics or Latinos of any race; 16.0% were of German, 9.0% English, 8.8% Irish, and 5.1% American ancestry; 83.5% spoke English, 6.3% Spanish, 1.7% Vietnamese, and 1.3% Russian as their first language.
Of the 272,098 households, 26.5% had children under 18 living with them, 40.9% were married couples living together, 10.8% had a female householder with no husband present, and 44.1% were not families. About 32.5% of all households were made up of individuals, and 8.6% had someone living alone who was 65 or older. The average household size was 2.37, and the average family size was 3.03.
 In the county, the age distribution was 22.3% under 18, 10.3% from 18 to 24, 33.8% from 25 to 44, 22.5% from 45 to 64, and 11.1% who were 65 or older. The median age was 35 years. For every 100 females, there were 98.00 males. For every 100 females 18 and over, there were 96.10 males.
 The median income for a household in the county was $41,278, and for a family was $51,118. Males had a median income of $36,036 versus $29,337 for females. The per capita income for the county was $22,606. 12.70% of the population and 8.20% of families were below the poverty line. Out of the total population, 15.40% of those under the age of 18 and 9.80% of those 65 and older were living below the poverty line.
 Multnomah County was a strongly Republican county for much of the first half of the 20th century, but since 1964, it has been the strongest Democratic bastion in Oregon. The Democrats have failed to win a majority in the county only two times since then, in 1972 and 1980.
 As Multnomah County is by far the most populous county in Oregon, Democratic majorities in the county are often enough to swing the results in statewide elections. In 2008, Democratic challenger Jeff Merkley unseated incumbent two-term Senator Gordon Smith, though Smith carried 28 of Oregon's 36 counties. Merkley carried Multnomah County by over 142,000 votes, however, enough to allow him to defeat Smith by 59,100 votes.
 The county courthouse is located in downtown Portland. The Multnomah County Central Courthouse opened in 2020, replacing a century-old building nearby that was in need of seismic retrofitting.
 Map of Multnomah County Senate-Representative District Maps
 The principal industries of Multnomah County are manufacturing, transportation, wholesale and retail trade, and tourism. Since Oregon does not have a sales tax, it attracts shoppers from southwest Washington.
 The Port of Portland, established in 1891 and combined with the City of Portland's Commission of Public Docks in 1971, ranks third in total waterborne commerce on the West Coast, and 31st in the nation for total tonnage according to the 2009 American Association of Port Authorities' Port Industries Statistics.  Portland is one of the five largest auto import ports in the nation and is the West Coast's leading exporter of grain and lumber.[citation needed] The Port of Portland is also responsible for Portland International Airport (PDX) in the northeast section of Portland, the Troutdale Airport a few miles east of PDX in Multnomah County, the Hillsboro Airport to the west in Washington County, and Mulino State Airport to the south in Clackamas County.
 Out of the 199 cities and counties located in the five West Coast states,
Multnomah County ranked 198th in private sector job creation from 1997 to 2009.
 The county is home to a number of Portland-area attractions and venues, including Oregon Museum of Science and Industry, Portland Art Museum, Memorial Coliseum, Oregon Convention Center, Moda Center, Providence Park, Washington Park, Oregon Zoo, International Rose Test Garden, Lan Su Chinese Garden, Portland Japanese Garden, Hoyt Arboretum and Pittock Mansion.
 It is also home to the Historic Columbia River Highway, Multnomah Falls, and Oxbow Regional Park.
 School districts include:
 Portland Community College serves western portions of the county and Mt. Hood Community College serves eastern portions.
 45°32′N 122°25′W﻿ / ﻿45.54°N 122.41°W﻿ / 45.54; -122.41