Adjacent counties and county-equivalents

National protected areas

Top employers

In 2003, the top employers are listed in the table below.^[5]

2020 census

As of the 2020 census, there were 19,677 people living in the county.^{[citation needed]}

2010 census

As of the 2010 census, there were 19,687 people, 8,843 households, and 5,608 families living in the county. The population density was 5.4 inhabitants per square mile (2.1/km²). There were 11,413 housing units at an average density of 3.2 units per square mile (1.2 units/km²). The racial makeup of the county was 95.9% white, 0.9% American Indian, 0.3% Asian, 0.1% black or African American, 0.4% from other races, and 2.3% from two or more races. Those of Hispanic or Latino origin made up 2.3% of the population. In terms of ancestry, 31.5% were German, 15.7% were Irish, 15.3% were English, 10.2% were Norwegian, and 3.3% were American.

Of the 8,843 households, 23.2% had children under the age of 18 living with them, 52.0% were married couples living together, 7.4% had a female householder with no husband present, 36.6% were non-families, and 30.6% of all households were made up of individuals. The average household size was 2.20 and the average family size was 2.72. The median age was 48.9 years.

The median income for a household in the county was $30,823 and the median income for a family was $39,600. Males had a median income of $40,944 versus $24,965 for females. The per capita income for the county was $19,626. About 13.7% of families and 18.6% of the population were below the poverty line, including 28.2% of those under age 18 and 12.1% of those age 65 or over.

Cities

• Libby (county seat)
• Troy

Towns

• Eureka
• Rexford

Census-designated places

Other unincorporated communities