Liberty County is on the state's north line, so that it shares the US border with Canada. It abuts the Canadian province of Alberta. According to the U.S. Census Bureau, the county has a total area of, of which is land and is water.
As of the 2000 United States Census, of 2000, there were 2,158 people, 833 households, and 583 families living in the county. The population density was 2 people per square mile. There were 1,070 housing units at an average density of 1 per square mile. The racial makeup of the county was 99.21% White, 0.09% Native American, 0.32% Asian, 0.09% from other races, and 0.28% from two or more races. 0.19% of the population were Hispanic or Latino of any race. 39.0% were of German, 20.0% Norwegian, 7.2% English, 5.8% American and 5.0% Irish ancestry. 84.5% spoke English and 15.5% German as their first language. There were 833 households out of which 30.40% had children under the age of 18 living with them, 62.70% were married couplesliving together, 5.60% had a female householder with no husband present, and 29.90% were non-families. 27.90% of all households were made up of individuals and 14.00% had someone living alone who was 65 years of age or older. The average household size was 2.51 and the average family size was 3.11. The county population contained 25.80% under the age of 18, 5.80% from 18 to 24, 24.70% from 25 to 44, 24.10% from 45 to 64, and 19.70% who were 65 years of age or older. The median age was 42 years. For every 100 females there were 97.10 males. For every 100 females age 18 and over, there were 93.60 males. The median income for a household in the county was $30,284, and the median income for a family was $37,361. Males had a median income of $23,158 versus $16,579 for females. The per capita income for the county was $14,882. About 19.00% of families and 20.30% of the population were below the poverty line, including 28.90% of those under age 18 and 15.50% of those age 65 or over. Researchers William P. O'Hare and Kenneth M. Johnson described the county as typical of the northern Great Plains in being very thinly settled, almost fully dependent on agriculture, and lacking in urban areas. They noted that income can fluctuate substantially from year to year, depending on rainfall as well as grain and cattle prices, and that the 2000 Census recorded low incomes in 1999 after several years of drought. Also, the presence of Hutterite colonies in the county depresses per capita incomes because Hutterite families have significantly more children than the general population.
2010 census
As of the 2010 United States Census, there were 2,339 people, 822 households, and 537 families living in the county. The population density was. There were 1,043 housing units at an average density of. The racial makeup of the county was 98.2% white, 0.2% American Indian, 0.1% black or African American, 0.1% Asian, 0.2% from other races, and 1.2% from two or more races. Those of Hispanic or Latino origin made up 0.3% of the population. In terms of ancestry, 55.4% were German, 24.1% were Norwegian, 14.5% were Irish, 9.9% were English, and 1.4% were American. Of the 822 households, 23.7% had children under the age of 18 living with them, 59.5% were married couples living together, 4.7% had a female householder with no husband present, 34.7% were non-families, and 32.2% of all households were made up of individuals. The average household size was 2.36 and the average family size was 3.00. The median age was 44.6 years. The median income for a household in the county was $40,212 and the median income for a family was $44,957. Males had a median income of $35,788 versus $30,714 for females. The per capita income for the county was $19,097. About 12.4% of families and 19.5% of the population were below the poverty line, including 31.6% of those under age 18 and 15.6% of those age 65 or over.
