Klamath is an unincorporated, rural, census-designated place (CDP) in Del Norte County, California, situated on the mouth of the Klamath River. The population was 651 at the 2000 census. Klamath is at an elevation of 30 feet (9 m).
According to the United States Census Bureau, the CDP has a total area of 12.5 square miles (32.5 km²), all of it land.
As of the census of 2000, there were 651 people, 264 households, and 177 families residing in the CDP. The population density was 51.9 people per square mile (20.0/km²). There were 365 housing units at an average density of 29.1/sq mi (11.2/km²). The racial makeup of the CDP was 58.37% White, 34.25% Native American, 0.77% Asian, 2.15% from other races, and 4.45% from two or more races. 5.53% of the population were Hispanic or Latino of any race.
There were 264 households out of which 25.8% had children under the age of 18 living with them, 48.5% were married couples living together, 11.4% had a female householder with no husband present, and 32.6% were non-families. 27.3% of all households were made up of individuals and 10.2% had someone living alone who was 65 years of age or older. The average household size was 2.39 and the average family size was 2.83.
In the CDP the population was spread out with 24.4% under the age of 18, 8.6% from 18 to 24, 21.8% from 25 to 44, 24.4% from 45 to 64, and 20.7% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 110.7 males. For every 100 females age 18 and over, there were 104.1 males.
The median income for a household in the CDP was $29,231, and the median income for a family was $29,417. Males had a median income of $24,750 versus $22,500 for females. The per capita income for the CDP was $13,660. About 11.2% of families and 15.2% of the population were below the poverty line, including 13.5% of those under age 18 and 7.9% of those age 65 or over.
In the state legislature Klamath is located in the 4th Senate District, represented by Republican Sam Aanestad, and in the 1st Assembly District, represented by Democrat Patty Berg. Federally, Klamath is located in California's 1st congressional district, which has a Cook PVI of D +10 and is represented by Democrat Mike Thompson.