Clackamas County is a county located in the state of Oregon. The county was named after the Native Americans living in the area, the Clackamas Indians, who were part of the Chinookan people. As of 2000, the population is 338,391. According to the U.S. Census Bureau, the county has a total area of 4,867 km˛ (1,879 mi˛). 4,839 km˛ (1,868 mi˛) of it is land and 28 km˛ (11 mi˛, or 0.58%) of it is water. Its county seat is Oregon City6.

As of the census2 of 2000, there are 338,391 people, 128,201 households, and 91,663 families residing in the county. The population density is 70/km˛ (181/mi˛). There are 136,954 housing units at an average density of 28/km˛ (73/mi˛). The racial makeup of the county is 91.27% White, 2.45% Asian, 0.71% Native American, 0.66% Black or African American, 0.17% Pacific Islander, 2.28% from other races, and 2.46% from two or more races. 4.95% of the population are Hispanic or Latino of any race.

There are 128,201 households out of which 34.20% have children under the age of 18 living with them, 58.60% are married couples living together, 9.00% have a female householder with no husband present, and 28.50% are non-families. 22.00% of all households are made up of individuals and 7.80% have someone living alone who is 65 years of age or older. The average household size is 2.62 and the average family size is 3.07.

The median income for a household in the county is $52,080, and the median income for a family is $60,791. Males have a median income of $43,462 versus $30,891 for females. The per capita income for the county is $25,973. 6.60% of the population and 4.60% of families are below the poverty line. Out of the total population, 7.60% of those under the age of 18 and 5.10% of those 65 and older are living below the poverty line.

Neighboring areas include: Hood River County, Wasco County, Marion County, Yamhill County, Washington County, and Multnomah County.