Jefferson County's estimated 2026 population is 13,427 with a growth rate of 0.74% 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 17.72% since that time.
Data after 2023 is projected based on recent change
Overall: 47.1 years
Female: 47 years
Male: 47.1 years
There are 10,219 adults, (2,961 of whom are seniors) in Jefferson County.
Female: 6,315 (49.4%)
Male: 6,459 (50.6%)
The racial composition of Jefferson County includes 91.73% White, and smaller percentages for Native American, other race, Asian, Black or African American and multiracial populations.
Race | Population | Percentage (of total) |
|---|---|---|
| White | 11,717 | 91.73% |
| Two or more races | 698 | 5.46% |
| Native American | 188 | 1.47% |
| Other race | 117 | 0.92% |
| Asian | 50 | 0.39% |
| Black or African American | 4 | 0.03% |
Jefferson County's average per capita income is $51,669. Household income levels show a median of $95,490. The poverty rate stands at 5.72%.
Name | Median | Mean |
|---|---|---|
| Married Families | $122,754 | - |
| Families | $109,206 | $140,331 |
| Households | $95,490 | $123,428 |
| Non Families | $55,125 | $71,543 |
Average Income
Median Household Income
Poverty Rate
