Adjacent counties

National protected area

• Custer National Forest (part)

2020 census

As of the 2020 census, there were 1,415 people and 628 households in Carter County.^[11] Of the population, 96.7% were White, 0.2% Black or African American, 1.0% Native American, 0.1% Asian, and 1.9% two or more races. 1.1% were Hispanic. 1.0% had a different primary language to English. The county was 50.1% female, 49.9% male.^[11]

The median household income was $48,000, $6,970 below the median of Montana. 61.7% of the population aged over 16 were in the civilian labor force. 14.7% of the population were classed as living in poverty. 2.4% of the population had a disability. 92.5% of the population graduated high school, with 20.2% obtaining a bachelor's degree or higher. 86.5% of households had a computer, with 77.9% having broadband access.^[11]

2010 census

As of the 2010 census, there were 1,160 people, 532 households, and 354 families living in the county. The population density was 0.3 inhabitants per square mile (0.12/km²). There were 810 housing units at an average density of 0.2 per square mile (0.077/km²). The racial makeup of the county was 97.8% white, 0.9% American Indian, 0.1% black or African American, 0.1% Asian, 0.3% from other races, and 0.8% from two or more races. Those of Hispanic or Latino origin made up 0.7% of the population. In terms of ancestry, 41.5% were German, 19.6% were English, 18.8% were Norwegian, 12.3% were Irish, and 4.3% were American.

Of the 532 households, 20.5% had children under the age of 18 living with them, 59.4% were married couples living together, 4.3% had a female householder with no husband present, 33.5% were non-families, and 30.3% of all households were made up of individuals. The average household size was 2.16 and the average family size was 2.65. The median age was 50.2 years.

The median income for a household in the county was $35,703 and the median income for a family was $47,955. Males had a median income of $26,736 versus $18,274 for females. The per capita income for the county was $20,681. About 8.5% of families and 14.0% of the population were below the poverty line, including 20.4% of those under age 18 and 10.8% of those age 65 or over.

Town

• Ekalaka (county seat)

Census-designated place

• Alzada

Unincorporated communities

Former communities

• Capitol