Major highways

Transit

• Jefferson Lines

Adjacent counties

Protected areas

Lakes

2020 census

As of the 2020 census, there were 21,392 people, 9,084 households, and 5,178 families in the county.^[12] The population density was 9.7 inhabitants per square mile (3.7/km²) There were 10,374 housing units.

2010 census

As of the 2010 census, there were 21,100 people, 8,931 households, and 5,255 families in the county. The population density was 9.5 inhabitants per square mile (3.7/km²). There were 9,862 housing units at an average density of 4.4 per square mile (1.7/km²). The racial makeup of the county was 95.6% white, 1.4% American Indian, 0.7% black or African American, 0.5% Asian, 0.1% Pacific islander, 0.5% from other races, and 1.3% from two or more races. Those of Hispanic or Latino origin made up 1.7% of the population. In terms of ancestry, 56.5% were German, 27.6% were Norwegian, 7.2% were Irish, 6.0% were Russian, 5.2% were English, and 2.4% were American.

Of the 8,931 households, 25.6% had children under the age of 18 living with them, 47.3% were married couples living together, 7.5% had a female householder with no husband present, 41.2% were non-families, and 35.3% of all households were made up of individuals. The average household size was 2.17 and the average family size was 2.79. The median age was 42.0 years.

The median income for a household in the county was $44,620 and the median income for a family was $60,171. Males had a median income of $40,365 versus $27,549 for females. The per capita income for the county was $23,307. About 6.3% of families and 12.1% of the population were below the poverty line, including 14.5% of those under age 18 and 14.6% of those age 65 or over.

Population by decade

Cities

Census-designated places

• Spiritwood
• Ypsilanti

Unincorporated communities

Townships