As of the 2010 United States Census, there were 169,468 people, 67,028 households, and 42,052 families in the county. The population density was . There were 71,557 housing units at an average density of . The racial makeup of the county was 88.1% white, 3.8% black or African American, 2.5% American Indian, 1.5% Asian, 0.1% Pacific islander, 1.8% from other races, and 2.3% from two or more races. Those of Hispanic or Latino origin made up 4.1% of the population. In terms of ancestry, 43.8% were German, 17.7% were Norwegian, 11.6% were Irish, 6.8% were Dutch, 6.3% were English, and 3.2% were American.