Clallam County was formed on April 26, 1854.
As of the census of 2000, there were 64,525 people, 27,164 households, and 18,064 families residing in the county. The population density was 37 people per square mile (14/km²). There were 30,683 housing units at an average density of 18 per square mile (7/km²). The racial makeup of the county was 89.12% White, 0.84% Black or African American, 5.12% Native American, 1.13% Asian, 0.16% Pacific Islander, 1.18% from other races, and 2.44% from two or more races. 3.41% of the population were Hispanic or Latino of any race. 17.2% were of German, 13.1% English, 9.3% Irish, 8.3% United States or American and 6.0% Norwegian ancestry according to Census 2000. 5% spoke English and 3.2% Spanish as their first language.
There were 27,164 households out of which 25.70% had children under the age of 18 living with them, 53.90% were married couples living together, 9.00% had a female householder with no husband present, and 33.50% were non-families. 28.10% of all households were made up of individuals and 13.40% had someone living alone who was 65 years of age or older. The average household size was 2.31 and the average family size was 2.78.
In the county, the population was spread out with 22.00% under the age of 18, 7.10% from 18 to 24, 22.80% from 25 to 44, 26.90% from 45 to 64, and 21.30% who were 65 years of age or older. The median age was 44 years. For every 100 females there were 98.70 males. For every 100 females age 18 and over, there were 96.60 males.
The median income for a household in the county was $36,449, and the median income for a family was $44,381. Males had a median income of $35,452 versus $24,628 for females. The per capita income for the county was $19,517. About 8.90% of families and 12.50% of the population were below the poverty line, including 17.10% of those under age 18 and 6.80% of those age 65 or over.