Jackson County's population was estimated to be 13,500 in the year 2006, an increase of 817, or +6.4%, over the previous six years; it is the sixth fastest growing population in the state.
As of the U.S. Census in 2000, there were 12,657 people, 4,727 households, and 3,507 families residing in the county. The population density was 19 people per square mile (7/km²). There were 5,094 housing units at an average density of 8 per square mile (3/km²). The racial makeup of the county was 90.21% White, 6.84% Native American, 0.53% Black or African American, 0.17% Asian, 0.02% Pacific Islander, 0.39% from other races, and 1.84% from two or more races. Hispanic or Latino of any race were 1.49% of the population.
There were 4,727 households out of which 35.20% had children under the age of 18 living with them, 62.30% were married couples living together, 8.20% had a female householder with no husband present, and 25.80% were non-families. 22.70% of all households were made up of individuals and 11.50% had someone living alone who was 65 years of age or older. The average household size was 2.63 and the average family size was 3.09.
In the county the population was spread out with 28.30% under the age of 18, 6.80% from 18 to 24, 26.70% from 25 to 44, 23.40% from 45 to 64, and 14.90% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 96.80 males. For every 100 females age 18 and over, there were 93.80 males.
The median income for a household in the county was $40,451, and the median income for a family was $46,520. Males had a median income of $32,195 versus $22,305 for females. The per capita income for the county was $18,606. About 6.40% of families and 8.80% of the population were below the poverty line, including 12.50% of those under age 18 and 9.20% of those age 65 or over.