Population Changes in Clackamas CountyApril 8, 2019
The population in the Portland Tri-County Area (Clackamas, Multnomah, and Washington counties) reached 1,839,005 in 2018. These three counties made up 44 percent of the population of Oregon in 2018.
Since 1940, Clackamas County’s population has grown by an average annual rate of 2.7 percent, adding 362,295 residents to reach the current population of 419,425. During this same time period, Multnomah County’s population saw a slower annual average growth rate of 1.1 percent and Washington County experienced a higher annual average growth rate, at 3.8 percent.
Mobility — Where Are People Coming From?
The U.S. Census, American Community Survey estimated that 15.8 percent or 62,527 residents in Clackamas County (one year of age and older) moved from their present place of residence in 2017.
The largest portion of this population (51%) moved somewhere within Clackamas County and nearly one-third (30%) moved from a different county in the state. Significantly fewer people moved to the county from a different state (16%) or moved from abroad (3%).