As of the census of 2000, there were 40,664 people, 15,815 households, and 11,149 families residing in the county. The population density was 46 people per square mile (18/km2). There were 18,317 housing units at an average density of 20 per square mile (8/km2). The racial makeup of the county was 91.61% White, 0.22% Black or African American, 6.26% Native American, 0.33% Asian, 0.04% Pacific Islander, 0.31% from other races, and 1.22% from two or more races. 1.00% of the population were Hispanic or Latino of any race. 54.9% were of German and 8.1% Polish ancestry.