Clark County is a county in the U.S. state of South Dakota. As of the 2010 census, the population was 3,691. Its county seat is Clark. The county was created in 1873 and organized in 1881. It was named for Newton Clark, a Dakota Territory legislator in 1873.
Clark County terrain consists of rolling hills, dotted with lakes and ponds especially in the east central portion. The area is mostly devoted to agriculture. The county has a total area of 967 square miles (2,500 km), of which 958 square miles (2,480 km) is land and 9.9 square miles (26 km) (1.0%) is water.
As of the 2000 United States Census, there were 4,143 people, 1,598 households, and 1,110 families in the county. The population density was 4 people per square mile (2/km²). There were 1,880 housing units at an average density of 2 per square mile (1/km²). The racial makeup of the county was 98.65% White, 0.07% Black or African American, 0.60% Native American, 0.10% Asian, 0.02% Pacific Islander, 0.19% from other races, and 0.36% from two or more races. 0.48% of the population were Hispanic or Latino of any race. 44.2% were of German, 24.9% Norwegian and 5.0% English ancestry.
There were 1,598 households out of which 29.30% had children under the age of 18 living with them, 61.60% were married couples living together, 4.70% had a female householder with no husband present, and 30.50% were non-families. 28.10% of all households were made up of individuals and 16.40% had someone living alone who was 65 years of age or older. The average household size was 2.54 and the average family size was 3.14.
The county population contained 27.00% under the age of 18, 5.80% from 18 to 24, 22.00% from 25 to 44, 23.00% from 45 to 64, and 22.20% who were 65 years of age or older. The median age was 42 years. For every 100 females there were 97.40 males. For every 100 females age 18 and over, there were 97.40 males.
The median income for a household in the county was $30,208, and the median income for a family was $35,559. Males had a median income of $24,421 versus $19,543 for females. The per capita income for the county was $15,597. About 10.90% of families and 14.80% of the population were below the poverty line, including 20.10% of those under age 18 and 16.00% of those age 65 or over.
As of the 2010 United States Census, there were 3,691 people, 1,445 households, and 929 families residing in the county. The population density was 3.9 inhabitants per square mile (1.5/km). There were 1,710 housing units at an average density of 1.8 per square mile (0.69/km). The racial makeup of the county was 98.1% white, 0.2% black or African American, 0.1% Asian, 0.1% American Indian, 0.8% from other races, and 0.8% from two or more races. Those of Hispanic or Latino origin made up 1.7% of the population. In terms of ancestry, 52.0% were German, 29.4% were Norwegian, 9.7% were Irish, 7.8% were English, 5.4% were Swedish, and 3.5% were American.
Of the 1,445 households, 23.0% had children under the age of 18 living with them, 55.8% were married couples living together, 4.8% had a female householder with no husband present, 35.7% were non-families, and 32.5% of all households were made up of individuals. The average household size was 2.22 and the average family size was 2.79. The median age was 45.7 years.
The median income for a household in the county was $43,894 and the median income for a family was $55,575. Males had a median income of $33,606 versus $24,952 for females. The per capita income for the county was $23,909. About 7.5% of families and 13.1% of the population were below the poverty line, including 24.5% of those under age 18 and 12.6% of those age 65 or over.
Clark County South Dakota neighborhoods include: Alcester, Baltic, Black Hawk, Box Elder, Brandon, Buffalo Ridge, Camp Crook, Canton, Caputa, Central City, Chancellor, Colton, Creighton, Crooks, Custer, Deadwood, Dell Rapids, Elkton, Ellsworth Afb, Garretson, Hartford, Hermosa, Hill City, Howes, Humboldt, Keystone, Lead, Ludlow, Montrose, Nemo, New Underwood, North Sioux City, Owanka, Parker, Quinn, Rapid City, Renner, Rowena, Saint Onge, Scenic, Sherman, Silver City, Sioux Falls, Spearfish, Sturgis, Valley Springs, Wall, Wanblee, Wasta, Whitewood