As of the 2010 United States Census, there were 81,327 people, 33,809 households, and 21,403 families living in the county. The population density was . There were 37,276 housing units at an average density of . The racial makeup of the county was 89.2% white, 4.3% American Indian, 1.2% black or African American, 0.8% Asian, 0.1% Pacific islander, 0.6% from other races, and 3.6% from two or more races. Those of Hispanic or Latino origin made up 3.3% of the population. In terms of ancestry, 28.5% were German, 17.1% were Irish, 12.3% were English, 10.3% were Norwegian, and 4.5% were American.