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Polk County, Oregon facts for kids

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Polk County
Polk County Courthouse in Dallas
Polk County Courthouse in Dallas
Map of Oregon highlighting Polk County
Location within the U.S. state of Oregon
Map of the United States highlighting Oregon
Oregon's location within the U.S.
Country  United States
State  Oregon
Founded December 22, 1845
Named for James K. Polk
Seat Dallas
Largest city Salem (portion)
 • Total 744 sq mi (1,930 km2)
 • Land 741 sq mi (1,920 km2)
 • Water 3.1 sq mi (8 km2)  0.4%%
 • Total 87,433
 • Estimate 
89,164 Increase
 • Density 118/sq mi (46/km2)
Time zone UTC−8 (Pacific)
 • Summer (DST) UTC−7 (PDT)
Congressional district 5th

Polk County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 87,433. The county seat is Dallas. The county is named for James Knox Polk, the 11th president of the United States.

Polk County is part of the Salem, OR Metropolitan Statistical Area, which is also included in the Portland-Vancouver-Salem, OR-WA Combined Statistical Area. It is located in the Willamette Valley.


Lone tree near Perrydale Oregon
Agricultural field and tree near Perrydale

The Oregon Provisional Legislature created Polk County from Yamhill District on December 22, 1845, granting to it the entire southwestern portion of present-day Oregon to the California border. County boundaries were periodically changed to reflect the creation of Benton and Lincoln counties. Many other counties were subsequently carved out of these as settlement spread towards the south, leaving Polk County many counties away from its former border with California.

The first county seat was a settlement on the north side of Rickreall Creek named Cynthian (also known as Cynthia Ann). In 1852 city officials renamed Cynthian to Dallas after Vice President George M. Dallas, vice president (1845-1849) to James Polk. During the 1880s and 1890s, there were a series of unsuccessful efforts to move the county seat to nearby Independence.


According to the U.S. Census Bureau, the county has a total area of 744 square miles (1,930 km2), of which 741 square miles (1,920 km2) is land and 3.1 square miles (8.0 km2) (0.4%) is water.

About two thirds of Polk County, the western part, is forest, mostly of the coniferous and mixed varieties, bordering on temperate rain forest around Laurel Mountain, the wettest place in Oregon.

The eastern half of the county lies in the Willamette Valley. The Willamette River forms the eastern border of the county, separating it from neighboring Marion County.

Adjacent counties

National protected areas


Historical population
Census Pop.
1860 3,625
1870 4,701 29.7%
1880 6,601 40.4%
1890 7,858 19.0%
1900 9,923 26.3%
1910 13,469 35.7%
1920 14,181 5.3%
1930 16,858 18.9%
1940 19,989 18.6%
1950 26,317 31.7%
1960 26,523 0.8%
1970 35,349 33.3%
1980 45,203 27.9%
1990 49,541 9.6%
2000 62,380 25.9%
2010 75,403 20.9%
2020 87,433 16.0%
2021 (est.) 89,164 18.2%
U.S. Decennial Census
1790–1960 1900–1990
1990–2000 2010–2020

2020 census

As of the 2020 census, there were 87,433 people, 30,305 households,. The population density was 101.8 inhabitants per square mile (39.3/km2). There were 30,302 housing units at an average density of 40.9 per square mile (15.8/km2). The racial makeup of the county was 85.9% white, 2.1% American Indian, 1.9% Asian, 0.6% black or African American, 0.3% Pacific islander, 5.4% from other races, and 3.8% from two or more races. Those of Hispanic or Latino origin made up 12.1% of the population. In terms of ancestry, 22.4% were German, 16.4% were English, 10.4% were Irish, and 6.4% were American.

Of the 28,288 households, 32.4% had children under the age of 18 living with them, 54.2% were married couples living together, 10.3% had a female householder with no husband present, 30.9% were non-families, and 23.0% of all households were made up of individuals. The average household size was 2.60 and the average family size was 3.06. The median age was 37.1 years.

The median income for a household in the county was $50,975 and the median income for a family was $61,418. Males had a median income of $46,616 versus $35,371 for females. The per capita income for the county was $24,345. About 8.8% of families and 12.9% of the population were below the poverty line, including 17.2% of those under age 18 and 6.8% of those age 65 or over.



Census-designated places

Unincorporated communities


The major industries of the county are agriculture, forest products, manufacturing, and education. Polk County has the second-largest area devoted to viticulture in Oregon, at 1,322 acres (5.35 km2). Western Oregon University in Monmouth is a major employer.

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