As of the census of 2000, there were 29,846 people, 11,476 households, and 8,354 families residing in the county. The population density was 18/km² (46/sq mi). There were 16,761 housing units at an average density of 10/km² (26/sq mi). The racial makeup of the county was 98.83% White, 0.43% Black or African American, 0.07% Native American, 0.19% Asian, 0.02% Pacific Islander, 0.09% from other races, and 0.37% from two or more races. 0.44% of the population were Hispanic or Latino of any race. 36.1% were of German, 22.9% American, 9.6% English and 8.8% Irish ancestry according to Census 2000.
There were 11,476 households out of which 32.60% had children under the age of 18 living with them, 60.70% were married couples living together, 8.40% had a female householder with no husband present, and 27.20% were non-families. 23.50% of all households were made up of individuals and 10.60% had someone living alone who was 65 years of age or older. The average household size was 2.55 and the average family size was 3.00.
In the county the population was spread out with 25.10% under the age of 18, 7.80% from 18 to 24, 27.60% from 25 to 44, 24.60% from 45 to 64, and 14.90% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 97.20 males. For every 100 females age 18 and over, there were 93.80 males.
The median income for a household in the county was $32,238, and the median income for a family was $37,811. Males had a median income of $29,469 versus $20,673 for females. The per capita income for the county was $16,219. 13.30% of the population and 9.80% of families were below the poverty line. Out of the total people living in poverty, 16.60% are under the age of 18 and 13.90% are 65 or older.