Geographic features

• Cape Disappointment
• Columbia River
• Long Beach Peninsula
• Long Island
• Willapa Bay

Major highways

• U.S. Route 101
• State Route 6

Adjacent counties

• Grays Harbor County – north
• Lewis County – east
• Wahkiakum County – southeast
• Clatsop County, Oregon – south

National protected areas

• Lewis and Clark National Historical Park (part)
• Willapa National Wildlife Refuge

2010 census

As of the 2010 census, there were 20,920 people, 9,499 households, and 5,707 families living in the county.^[11] The population density was 22.4 inhabitants per square mile (8.6/km²). There were 15,547 housing units at an average density of 16.7 per square mile (6.4/km²).^[12] The racial makeup of the county was 87.4% white, 2.3% American Indian, 2.0% Asian, 0.4% black or African American, 0.1% Pacific islander, 4.4% from other races, and 3.4% from two or more races. Those of Hispanic or Latino origin made up 8.0% of the population.^[11] In terms of ancestry, 23.4% were German, 13.8% were English, 11.9% were Irish, 7.6% were American, 6.2% were Norwegian, and 5.8% were Swedish.^[13]

Of the 9,499 households, 20.7% had children under the age of 18 living with them, 47.6% were married couples living together, 8.1% had a female householder with no husband present, 39.9% were non-families, and 33.0% of all households were made up of individuals. The average household size was 2.17 and the average family size was 2.72. The median age was 50.8 years.^[11]

The median income for a household in the county was $39,642 and the median income for a family was $51,450. Males had a median income of $44,775 versus $34,538 for females. The per capita income for the county was $23,326. About 12.4% of families and 16.8% of the population were below the poverty line, including 20.4% of those under age 18 and 9.9% of those age 65 or over.^[14]

2000 census

As of the 2000 census, there were 20,984 people, 9,096 households, and 5,885 families living in the county. The population density was 22 people per square mile (8.5 people/km²). There were 13,991 housing units at an average density of 15 per square mile (5.8/km²). The racial makeup of the county was 90.54% White, 0.20% Black or African American, 2.44% Native American, 2.08% Asian, 0.09% Pacific Islander, 1.83% from other races, and 2.82% from two or more races. 5.01% of the population were Hispanic or Latino of any race. 18.0% were of German, 10.8% English, 8.8% Irish and 8.6% United States or American ancestry.

There were 9,096 households, out of which 23.10% had children under the age of 18 living with them, 53.10% were married couples living together, 7.90% had a female householder with no husband present, and 35.30% were non-families. 29.50% of all households were made up of individuals, and 14.30% had someone living alone who was 65 years of age or older. The average household size was 2.27 and the average family size was 2.77.

In the county, the population was spread out, with 21.40% under the age of 18, 6.00% from 18 to 24, 21.20% from 25 to 44, 28.90% from 45 to 64, and 22.60% who were 65 years of age or older. The median age was 46 years. For every 100 females there were 98.30 males. For every 100 females age 18 and over, there were 95.80 males.

The median income for a household in the county was $31,209, and the median income for a family was $39,302. Males had a median income of $33,892 versus $22,982 for females. The per capita income for the county was $17,322. About 9.10% of families and 14.40% of the population were below the poverty line, including 19.70% of those under age 18 and 8.10% of those age 65 or over.

Cities

• Ilwaco
• Long Beach
• Raymond
• South Bend (county seat)

Census-designated places

• Bay Center
• Chinook
• Lebam
• Naselle
• Ocean Park
• Tokeland
• Willapa

Unincorporated communities