As of the census of 2000, there were 13,674 people, 4,556 households, and 3,366 families residing in the county. The population density was 15 people per square mile (6/km²). There were 5,027 housing units at an average density of 6 per square mile (2/km²). The racial makeup of the county was 25.12% White, 0.07% Black or African American, 73.01% Native American, 0.07% Asian, 0.12% from other races, and 1.61% from two or more races. 0.80% of the population were Hispanic or Latino of any race. 9.3% were of Norwegian and 7.4% German ancestry according to Census 2000. 94.6% spoke English, 1.3% Ojibwa, 1.0% French Cree and 1.0% Cree as their first language.
There were 4,556 households out of which 43.80% had children under the age of 18 living with them, 44.00% were married couples living together, 22.70% had a female householder with no husband present, and 26.10% were non-families. 22.60% of all households were made up of individuals and 9.50% had someone living alone who was 65 years of age or older. The average household size was 2.97 and the average family size was 3.45.
In the county the population was spread out with 36.50% under the age of 18, 9.50% from 18 to 24, 25.80% from 25 to 44, 18.50% from 45 to 64, and 9.70% who were 65 years of age or older. The median age was 29 years. For every 100 females there were 97.20 males. For every 100 females age 18 and over, there were 91.90 males.
The median income for a household in the county was $26,232, and the median income for a family was $29,744. Males had a median income of $24,288 versus $20,383 for females. The per capita income for the county was $10,873. About 28.00% of families and 31.00% of the population were below the poverty line, including 39.20% of those under age 18 and 19.60% of those age 65 or over.