As of the 2010 United States Census, there were 3,976 people, 1,748 households, and 1,185 families in the county. The population density was . There were 2,636 housing units at an average density of . The racial makeup of the county was 96.1% white, 1.0% American Indian, 0.4% Asian, 0.1% Pacific islander, 0.1% black or African American, 0.7% from other races, and 1.7% from two or more races. Those of Hispanic or Latino origin made up 2.4% of the population. In terms of ancestry, 26.3% were German, 18.0% were English, 14.6% were Irish, and 4.9% were American.