As of the 2010 United States Census, there were 20,778 people and 8,040 households. The population density was 28 people per square mile (10.7/km2). There were 9,221 housing units at an average density of 12.3 per square mile (4.75/km2). The racial makeup of the county was 98.2% White, 0.6% Black or African American, 0.6% Native American, 0.6% Asian, 0.00% Pacific Islander, 1.0% from other races, and 1.1% from two or more races. 2.0% of the population were Hispanic or Latino of any race.