Etna is located at . This is in Northern California near the Oregon border. Etna is located in Scott Valley next to the CPD of Greenview and the city of Fort Jones. Etna is located at the foot of the Marble Mountain Wilderness in the Siskiyou Mountain (Cascades) Range and is an attraction for hikers, rafters, climbers and people who do all sorts of other outdoor activities. According to the United States Census Bureau, the city has a total area of 0.8 square miles (2.0 km²), all of it land.(41.457350, -122.896875)
As of the census of 2000, there were 781 people, 329 households, and 210 families residing in the city. The population density was 989.9 people per square mile (381.7/km²). There were 362 housing units at an average density of 458.8/sq mi (176.9/km²). The racial makeup of the city was 88.48% White, 0.13% African American, 6.02% Native American, 0.64% Asian, 1.02% from other races, and 3.71% from two or more races. Hispanic or Latino of any race were 3.46% of the population.
There were 329 households out of which 28.0% had children under the age of 18 living with them, 48.9% were married couples living together, 11.6% had a female householder with no husband present, and 35.9% were non-families. 31.0% of all households were made up of individuals and 17.6% had someone living alone who was 65 years of age or older. The average household size was 2.37 and the average family size was 2.98.
In the city the population was spread out with 26.1% under the age of 18, 4.7% from 18 to 24, 21.4% from 25 to 44, 25.1% from 45 to 64, and 22.7% who were 65 years of age or older. The median age was 44 years. For every 100 females there were 95.3 males. For every 100 females age 18 and over, there were 93.6 males.
The median income for a household in the city was $25,179, and the median income for a family was $30,461. Males had a median income of $25,972 versus $20,750 for females. The per capita income for the city was $13,737. About 13.7% of families and 19.7% of the population were below the poverty line, including 23.5% of those under age 18 and 9.1% of those age 65 or over.
In the state legislature Etna is located in the 4th Senate District, represented by Republican Sam Aanestad, and in the 2nd Assembly District, represented by Republican Doug LaMalfa. Federally, Etna is located in California's 2nd congressional district, which has a Cook PVI of R +13 and is represented by Republican Wally Herger.