Multnomah County /mʌltˈnoʊmə/ is one of 36 counties in the U.S. state of Oregon. As of the 2010 United States Census, the county’s population was 735,334. Its county seat, Portland, is the state’s largest city. Multnomah County is part of the Portland-Vancouver-Hillsboro, OR-WA Metropolitan Statistical Area, and though smallest in area, it is the state’s most populous county.
According to the United States Census Bureau, the county has a total area of 466 square miles (1,210 km), of which 431 square miles (1,120 km) is land and 34 square miles (88 km) (7.4%) is 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 2000 census, there are 660,486 people in the county, organized into 272,098 households and 152,102 families. The population density is 1,518 people per square mile (586/km²). There are 288,561 housing units at an average density of 663 per square mile (256/km²). The racial makeup of the county is 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. 7.51% of the population are Hispanic or Latino 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.
There are 272,098 households out of which 26.5% have children under the age of 18 living with them, 40.9% are married couples living together, 10.8% have a female householder with no husband present, and 44.1% are non-families. 32.5% of all households are made up of individuals and 8.6% have someone living alone who is 65 years of age or older. The average household size is 2.37 and the average family size is 3.03.
In the county, the population is spread out with 22.30% under the age of 18, 10.30% from 18 to 24, 33.80% from 25 to 44, 22.50% from 45 to 64, and 11.10% who are 65 years of age or older. The median age is 35 years. For every 100 females, there are 98.00 males. For every 100 females age 18 and over, there are 96.10 males.
The median income for a household in the county is $41,278, and the median income for a family is $51,118. Males have a median income of $36,036 versus $29,337 for females. The per capita income for the county is $22,606. 12.70% of the population and 8.20% of families are 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 are living below the poverty line.
As of the 2010 United States Census, there were 735,334 people, 304,540 households, and 163,539 families residing in the county. The population density was 1,704.9 inhabitants per square mile (658.3/km). There were 324,832 housing units at an average density of 753.2 per square mile (290.8/km). 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 the age of 18 living with them, 38.6% were married couples living together, 10.7% had a female householder with no husband present, 46.3% were non-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 the median income 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.