Mellette County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 1,918. Its county seat is White River. The county was created in 1909, and was organized in 1911. It was named for Arthur C. Mellette, the last Governor of the Dakota Territory and the first Governor of the state of South Dakota. Historically territory of the Sioux/Lakota peoples, 33.35 percent of the county's land is trust land associated with the Rosebud Indian Reservation in the neighboring county to the south. According to the 2000 United States Census, 52.2% of the population is Native American, mostly the federally recognized Sicangu Oyate (Upper Brulé Sioux) and the Rosebud Sioux Tribe, a branch of the Lakota people.

Geography

The White River flows eastward along the north boundary line of Mellette County. The Little White River flows northward through central Mellette County, discharging into White River. The terrain consists of semi-arid rolling hills, the northern portion dotted with ponds and small lakes. The area is mostly devoted to agriculture. The terrain slopes to the northeast; its highest point is the SW corner at 2,779 ft ASL. The county has a total area of 1311 sqmi, of which 1307 sqmi is land and 3.6 sqmi (0.3%) is water. The eastern portion of South Dakota's counties (48 of 66) observe Central Time; the western counties (18 of 66) observe Mountain Time. Mellette County is the westernmost of the SD counties to observe Central Time.

Major highways

Adjacent counties

Demographics

2020 census

As of the 2020 census, there were 1,918 people, 651 households, and 419 families residing in the county. The population density was 1.5 PD/sqmi. There were 775 housing units.

2010 census

As of the 2010 census, there were 2,048 people, 693 households, and 493 families in the county. The population density was 1.6 PD/sqmi. There were 838 housing units at an average density of 0.6 /mi2. The racial makeup of the county was 54.1% American Indian, 39.7% white, 0.2% Asian, 0.1% black or African American, 0.2% from other races, and 5.6% from two or more races. Those of Hispanic or Latino origin made up 1.5% of the population. In terms of ancestry, 25.6% were German, 8.4% were Irish, 6.1% were English, and 0.6% were American. Of the 693 households, 41.6% had children under the age of 18 living with them, 43.3% were married couples living together, 19.0% had a female householder with no husband present, 28.9% were non-families, and 24.7% of all households were made up of individuals. The average household size was 2.88 and the average family size was 3.38. The median age was 34.2 years. The median income for a household in the county was $34,055 and the median income for a family was $35,781. Males had a median income of $31,625 versus $30,956 for females. The per capita income for the county was $16,971. About 23.4% of families and 27.0% of the population were below the poverty line, including 40.5% of those under age 18 and 6.3% of those age 65 or over.

Communities

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Town

Census-designated places

Unincorporated communities

Townships

Unorganized territories

Politics

Like most of South Dakota, Mellette County is solidly Republican. It has not been carried by a Democrat since Lyndon Johnson’s 1964 landslide, although Barack Obama came within six votes of doing so in the 2012 election.