The 2010 census recorded a population of 11,581 in the county, with a population density of 19.7123/sq mi. There were 4,848 housing units, of which 4,442 were occupied.
As of the census of 2000, there were 11,763 people, 4,428 households, and 3,263 families residing in the county. The population density was 20 people per square mile. There were 4,758 housing units at an average density of 8 per square mile. The racial makeup of the county was 99.13% White, 0.09% Black or African American, 0.14% Native American, 0.15% Asian, 0.01% Pacific Islander, 0.10% from other races, and 0.37% from two or more races. 0.36% of the population were Hispanic or Latino of any race.
There were 4,428 households out of which 34.80% had children under the age of 18 living with them, 67.10% were married couples living together, 4.40% had a female householder with no husband present, and 26.30% were non-families. 24.30% of all households were made up of individuals and 13.70% had someone living alone who was 65 years of age or older. The average household size was 2.61 and the average family size was 3.13.
In the county the population was spread out with 28.00% under the age of 18, 7.60% from 18 to 24, 24.60% from 25 to 44, 20.90% from 45 to 64, and 18.80% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 98.40 males. For every 100 females age 18 and over, there were 94.60 males.
The median income for a household in the county was $36,878, and the median income for a family was $45,144. Males had a median income of $29,462 versus $19,385 for females. The per capita income for the county was $16,081. About 4.90% of families and 7.00% of the population were below the poverty line, including 7.90% of those under age 18 and 10.30% of those age 65 or over.