As of the census of 2000, there were 32,584 people, 13,356 households, and 9,015 families residing in the county. The population density was 46 people per square mile (18/km²). There were 13,996 housing units at an average density of 20 per square mile (8/km²). The racial makeup of the county was 95.22% White, 0.24% Black or African American, 0.20% Native American, 0.55% Asian, 0.02% Pacific Islander, 2.92% from other races, and 0.85% from two or more races. 6.29% of the population were Hispanic or Latino of any race. 34.8% were of Norwegian, 26.2% German and 5.8% Danish ancestry according to Census 2000.
There were 13,356 households out of which 29.10% had children under the age of 18 living with them, 56.50% were married couples living together, 7.50% had a female householder with no husband present, and 32.50% were non-families. 28.20% of all households were made up of individuals and 14.00% had someone living alone who was 65 years of age or older. The average household size was 2.40 and the average family size was 2.92.
In the county the population was spread out with 24.00% under the age of 18, 7.50% from 18 to 24, 25.50% from 25 to 44, 24.10% from 45 to 64, and 18.90% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 96.60 males. For every 100 females age 18 and over, there were 95.00 males.
The median income for a household in the county was $36,964, and the median income for a family was $45,142. Males had a median income of $31,491 versus $21,799 for females. The per capita income for the county was $18,325. About 5.60% of families and 8.40% of the population were below the poverty line, including 9.00% of those under age 18 and 9.10% of those age 65 or over.