Population of Counties in Oregon (2020)
The most populous county in Oregon in 2019 is Multnomah County, home of Portland, with a population of 811,880. This represents population growth of 10.12% since the 2010 census. After Multnomah County is Washington County (597,695), Clackamas County (416,075), Lane County (379,611), Marion County (346,868), and Jackson County (219,564). These are the only counties with a population of more than 200,000. Of these counties, Washington County experienced the most dramatic population growth of 12.42% since the census.
Oregon Counties with Fewest Residents
The least populous county in Oregon is Wheeler County with 1,366 residents, a decline of 5.60% since the census. There are seven counties in Oregon with a population below 10,000. Other small counties in Oregon include Sherman County (1,708), Gilliam County (1,894), Wallowa County (7,081), Grant County (7,176), Harney County (7,329), and Lake County (7,879). Of these counties, only three have experienced positive or neutral growth. Wheeler County experienced the most dramatic decline.
Oregon Counties with Rapid Growth
Deschutes County, Oregon experienced the most rapid growth in the state since the census, growing 21.71% to 191,996 residents in 2019. Other counties that have experienced substantial growth include Crook County (14.28%), Polk County (12.83%), Washington County (12.42%), and Jefferson County (11.69%). Only six counties experienced decline since the census. The most significant decline was in Wheeler County (-5.60%) followed by Sherman County (-3.99%) and Grant County (-3.86%).