Gregory County lies on the south line of South Dakota. Its south boundary line abuts the north boundary line of Nebraska. The Missouri River flows southeastward along its east boundary line. The county terrain consists of rolling hills, sloping to the southeast. The eastern part of the county is etched with gullies and drainages, flowing to the river basin.[5] The county's highest point is in the SW corner, at 2,247 ft (685 m) ASL.[6]
Gregory County has a total area of 1,054 square miles (2,730 km2), of which 1,015 square miles (2,630 km2) is land and 39 square miles (100 km2) (3.7%) is water.[7]
U.S. Decennial Census[9] 1790-1960[10] 1900-1990[11] 1990-2000[12] 2010-2020[1]
2020 census
As of the 2020 census, there were 3,994 people, 1,721 households, and 1,070 families residing in the county.[13] The population density was 3.9 inhabitants per square mile (1.5/km2). There were 2,186 housing units.
2010 census
As of the 2010 census, there were 4,271 people, 1,936 households, and 1,172 families in the county. The population density was 4.2 inhabitants per square mile (1.6/km2). There were 2,503 housing units at an average density of 2.5 units per square mile (0.97 units/km2). The racial makeup of the county was 89.6% white, 7.5% American Indian, 0.3% Asian, 0.2% black or African American, 0.2% from other races, and 2.2% from two or more races. Those of Hispanic or Latino origin made up 0.9% of the population. In terms of ancestry, 54.5% were German, 11.4% were Irish, 10.9% were Czech, 7.1% were English, 6.0% were Norwegian, and 2.4% were American.
Of the 1,936 households, 23.7% had children under the age of 18 living with them, 49.9% were married couples living together, 7.4% had a female householder with no husband present, 39.5% were non-families, and 36.6% of all households were made up of individuals. The average household size was 2.18 and the average family size was 2.84. The median age was 48.2 years.
The median income for a household in the county was $33,940 and the median income for a family was $44,333. Males had a median income of $30,401 versus $25,804 for females. The per capita income for the county was $21,311. About 10.7% of families and 16.0% of the population were below the poverty line, including 27.1% of those under age 18 and 19.2% of those age 65 or over.
Farming and ranching are two main economic factors of the county.
Politics
Like all of South Dakota outside Native American counties, Gregory County is powerfully Republican. No Democrat has carried Gregory County since Jimmy Carter in 1976. Like almost all of rural America, recent swings away from the Democratic Party have been very rapid: Donald Trump's 79.0 percent of the county's vote is the largest any candidate has obtained in the county since South Dakota statehood.
United States presidential election results for Gregory County, South Dakota[17]
