As of the 2010 United States Census, there were 3,651 people, 1,590 households, and 1,045 families in the county. The population density was . There were 2,148 housing units at an average density of . The racial makeup of the county was 96.6% white, 0.7% Asian, 0.4% American Indian, 0.1% black or African American, 0.6% from other races, and 1.5% from two or more races. Those of Hispanic or Latino origin made up 1.4% of the population. In terms of ancestry, 25.3% were German, 22.6% were Norwegian, 13.0% were American, 12.8% were Irish, 10.8% were English, and 7.3% were Scottish.