Ziebach County is a county in the U.S. state of South Dakota. As of the 2010 United States Census, the population was 2,801. Its county seat is Dupree. It is the last county in the United States alphabetically.
The Cheyenne River flows east-northeastward along the southern boundary of Ziebach County. The Moreau River flows eastward through the upper portion of the county, and Cherry Creek flows southeastward through the lower portion, draining the area into the Cheyenne River. The terrain is composed of semi-arid rolling hills interrupted by buttes and carved by drainages and gullies, partly devoted to agriculture and cattle. The terrain slopes to the south and the east; its highest point (except for the isolated Thunder Butte, at 2,733′) is near its NW corner at 2,582′ (787m) ASL. The county has a total area of 1,971 square miles (5,100 km), of which 1,961 square miles (5,080 km) is land and 9.3 square miles (24 km) (0.5%) is water. Almost the entire county lies within the Cheyenne River Indian Reservation. The balance of the county, along its extreme northern county line, lies within the Standing Rock Indian Reservation. It is one of five South Dakota counties that lie entirely on Indian reservations.
As of the 2000 United States Census, there were 2,519 people, 741 households, and 594 families in the county. The population density was 1.3 people per square mile (0.5/km²). There were 879 housing units at an average density of 0.4 per square mile (0.2/km²). The racial makeup of the county was 72.29% Native American, 26.40% White, 0.08% Asian, 0.12% from other races, and 1.11% from two or more races. 0.99% of the population were Hispanic or Latino of any race.
There were 741 households out of which 47.2% had children under the age of 18 living with them, 47.9% were married couples living together, 23.8% had a female householder with no husband present, and 19.8% were non-families. 17.4% of all households were made up of individuals and 5.1% had someone living alone who was 65 years of age or older. The average household size was 3.40 and the average family size was 3.81.
The county population contained 40.6% under the age of 18, 10.8% from 18 to 24, 24.7% from 25 to 44, 16.5% from 45 to 64, and 7.5% who were 65 years of age or older. The median age was 24 years. For every 100 females there were 97.0 males. For every 100 females age 18 and over, there were 98.1 males.
The median income for a household in the county was $18,063, and the median income for a family was $18,672. Males had a median income of $19,038 versus $21,167 for females. The per capita income for the county was $7,463. About 45.20% of families and 49.90% of the population were below the poverty line, including 61.10% of those under age 18 and 27.20% of those age 65 or over. In 2009, it was one of 17 counties in the United States where half of all children live in poverty.
As of the 2010 United States Census, there were 2,801 people, 836 households, and 638 families in the county. The population density was 1.4 inhabitants per square mile (0.54/km). There were 987 housing units at an average density of 0.5 per square mile (0.19/km). The racial makeup of the county was 74.9% American Indian, 21.8% white, 0.2% black or African American, 0.1% Asian, 0.1% from other races, and 3.0% from two or more races. Those of Hispanic or Latino origin made up 3.1% of the population.
Of the 836 households, 53.7% had children under the age of 18 living with them, 39.0% were married couples living together, 29.3% had a female householder with no husband present, 23.7% were non-families, and 20.9% of all households were made up of individuals. The average household size was 3.35 and the average family size was 3.82. The median age was 25.4 years.
The median income for a household in the county was $27,578 and the median income for a family was $22,857. Males had a median income of $28,954 versus $24,327 for females. The per capita income for the county was $11,069. About 41.9% of families and 46.0% of the population were below the poverty line, including 56.1% of those under age 18 and 22.9% of those age 65 or over.
Ziebach 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