Major highways

Adjacent counties

Protected areas

Source:^[5]

Lakes

Source:^[5]

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.

Cities

• Bonesteel
• Burke (County Seat)
• Gregory

Towns

• Dallas
• Fairfax
• Herrick

Census-designated place

• St. Charles

Unincorporated communities

• Carlock^[14]
• Dixon^[15]
• Lucas^[16]

Townships

Unorganized territories