Yellowstone County's 2026 population is estimated at 173,295, reflecting a 0.5% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Yellowstone County is the largest county in Montana. The 2010 population was 148,405 and has grown 16.77% since 2010.
Data after 2023 is projected based on recent change
Overall: 39 years
Female: 40 years
Male: 38.3 years
There are 130,154 adults, (30,892 of whom are seniors) in Yellowstone County.
Female: 85,196 (50.4%)
Male: 83,761 (49.6%)
The racial composition of Yellowstone County includes 85.55% White, 3.95% Native American, and smaller percentages for other race, Asian, Black or African American, Native Hawaiian or Pacific Islander and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 144,550 | 85.55% |
| Two or more races | 12,248 | 7.25% |
| Native American | 6,682 | 3.95% |
| Other race | 2,962 | 1.75% |
| Asian | 1,298 | 0.77% |
| Black or African American | 1,146 | 0.68% |
| Native Hawaiian or Pacific Islander | 71 | 0.04% |
Yellowstone County 's average per capita income is $49,616. Household income levels show a median of $76,570. The poverty rate stands at 9.19%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $115,288 | $146,459 |
| Families | $99,949 | $128,013 |
| Households | $76,570 | $104,900 |
| Non Families | $46,445 | $64,349 |
Average Income
Median Household Income
Poverty Rate
