In 2021, Jefferson County, MT had a population of 12.1k people with a median age of 47.5 and a median household income of $72,500. Between 2020 and 2021 the population of Jefferson County, MT declined from 12,069 to 12,057, a −0.0994% decrease and its median household income grew from $71,779 to $72,500, a 1% increase.
The 5 largest ethnic groups in Jefferson County, MT are White (Non-Hispanic) (91.5%), Two+ (Non-Hispanic) (4.12%), White (Hispanic) (1.83%), American Indian & Alaska Native (Non-Hispanic) (0.946%), and Black or African American (Non-Hispanic) (0.448%).
None of the households in Jefferson County, MT reported speaking a non-English language at home as their primary shared language. This does not consider the potential multi-lingual nature of households, but only the primary self-reported language spoken by all members of the household.
99.4% of the residents in Jefferson County, MT are U.S. citizens.
In 2021, the median property value in Jefferson County, MT was $304,300, and the homeownership rate was 84.1%.
Most people in Jefferson County, MT drove alone to work, and the average commute time was 22.7 minutes. The average car ownership in Jefferson County, MT was 3 cars per household.