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

Jefferson County Population

Data after 2023 is projected based on recent change

Demographics

The racial composition of Jefferson County includes 92.81% White, and smaller percentages for Native American, other race, Asian, Black or African American and multiracial populations.

Population by Race

Race
Population
Percentage (of total)
White11,60292.81%
Two or more races5964.77%
Native American1651.32%
Other race730.58%
Asian510.41%
Black or African American140.11%

Jefferson County Marital Status

OverallMalesFemales0%10%20%30%40%50%60%70%80%90%100%

Married

Widowed

Divorced

Separated

Never Married

Economics and Income Statistics

Jefferson County's average per capita income is $44,682. Household income levels show a median of $76,576. The poverty rate stands at 6.29%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.
Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.
Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.
Name
Median
Mean
Married Families$105,382-
Families$97,578$123,542
Households$76,576$107,580
Non Families$46,147$58,288

$44,682

Average Income

$76,576

Median Household Income

6.29%

Poverty Rate