As of the 2000 United States Census, of 2000, there were 11,893 people, 4,860 households, and 3,197 families living in the county. The population density was 3 people per square mile. There were 5,558 housing units at an average density of 1 per square mile. The racial makeup of the county was 97.10% White, 1.18% Native American, 0.19% Asian, 0.29% from other races, 0.08% Black or African American, and 1.16% from two or more races. 0.81% of the population were Hispanic or Latino of any race. 24.5% were of German, 13.5% American, 13.0% Norwegian, 9.3% Irish and 9.0% English ancestry. 97.1% spoke English, 1.2% German, and 1.1% Spanish as their first language. There were 4,860 households out of which 28.70% had children under the age of 18 living with them, 56.10% were married couplesliving together, 6.70% had a female householder with no husband present, and 34.20% were non-families. 30.50% of all households were made up of individuals and 13.90% had someone living alone who was 65 years of age or older. The average household size was 2.33 and the average family size was 2.91. The county population contained 24.50% under the age of 18, 6.10% from 18 to 24, 23.60% from 25 to 44, 25.80% from 45 to 64, and 19.90% who were 65 years of age or older. The median age was 42 years. For every 100 females there were 94.80 males. For every 100 females age 18 and over, there were 93.40 males. The median income for a household in the county was $30,409, and the median income for a family was $36,609. Males had a median income of $27,260 versus $18,138 for females. The per capita income for the county was $15,808. About 10.60% of families and 15.40% of the population were below the poverty line, including 19.40% of those under age 18 and 12.20% of those age 65 or over.
2010 census
As of the 2010 United States Census, there were 11,586 people, 5,099 households, and 3,202 families living in the county. The population density was. There were 5,836 housing units at an average density of. The racial makeup of the county was 96.6% white, 1.2% American Indian, 0.2% black or African American, 0.2% Asian, 0.2% from other races, and 1.5% from two or more races. Those of Hispanic or Latino origin made up 1.5% of the population. In terms of ancestry, 30.8% were German, 15.9% were English, 14.7% were Norwegian, 12.8% were Irish, and 4.2% were American. Of the 5,099 households, 23.8% had children under the age of 18 living with them, 52.9% were married couples living together, 6.5% had a female householder with no husband present, 37.2% were non-families, and 32.6% of all households were made up of individuals. The average household size was 2.18 and the average family size was 2.75. The median age was 47.8 years. The median income for a household in the county was $37,607 and the median income for a family was $48,623. Males had a median income of $35,110 versus $21,225 for females. The per capita income for the county was $22,295. About 12.5% of families and 14.7% of the population were below the poverty line, including 24.2% of those under age 18 and 9.3% of those age 65 or over.
