Jefferson County Flag

Jefferson County

State:
Montana
County Seat:
Boulder

Jefferson County's estimated 2025 population is 13,482 with a growth rate of 1.64% in the past year according to the most recent United States census data. Jefferson County is the 15th largest county in Montana. The 2010 population was 11,406 and has seen a growth of 18.2% since that time.

13,482
Total Population
8
Population Density (mi²)
15
Population Rank (State)
217 1.64%
Annual Population Growth

Jefferson County Population

Demographics

Economics and Income Statistics