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.
Jefferson County, MT borders Broadwater County, MT, Deer Lodge County, MT, Gallatin County, MT, Lewis and Clark County, MT, Madison County, MT, Powell County, MT, and Silver Bow County, MT.