Jefferson County's estimated 2026 population is 13,740 with a growth rate of 1.61% in the past year according to the most recent United States census data. Jefferson County is the 14th largest county in Montana. The 2010 population was 11,406 and has seen a growth of 20.46% since that time.
Data after 2023 is projected based on recent change
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.
White (92.81%)
Two or more races (4.77%)
Native American (1.32%)
Other race (0.58%)
Asian (0.41%)
Black or African American (0.11%)
Race | Population | Percentage (of total) |
|---|---|---|
| White | 11,602 | 92.81% |
| Two or more races | 596 | 4.77% |
| Native American | 165 | 1.32% |
| Other race | 73 | 0.58% |
| Asian | 51 | 0.41% |
| Black or African American | 14 | 0.11% |
Married
Widowed
Divorced
Separated
Never Married
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%.
Name | Median | Mean |
|---|---|---|
| Married Families | $105,382 | - |
| Families | $97,578 | $123,542 |
| Households | $76,576 | $107,580 |
| Non Families | $46,147 | $58,288 |
Average Income
Median Household Income
Poverty Rate
