As of the 2010 census, there were 17,959 people, 7,326 households, and 4,818 families residing in the county. The population density was 36 people per square mile (13/km2). There were 8,927 housing units at an average density of 15 per square mile (6/km2). The racial makeup of the county was 98.1% White, 0.2% Black or African American, 0.2% Native American, 0.2% Asian, 0.4% from other races, and 0.9% from two or more races. 1.1% of the population were Hispanic or Latino of any race.