Petroleum County's estimated 2026 population is 489 with a growth rate of -3.55% in the past year according to the most recent United States census data. Petroleum County is the 56th largest county in Montana. The 2010 population was 489 and has seen a growth of 0% since that time.
Data after 2023 is projected based on recent change
The racial composition of Petroleum County includes 99.25% White, and smaller percentages for Asian and multiracial populations.
White (99.25%)
Asian (0.75%)
Race | Population | Percentage (of total) |
|---|---|---|
| White | 398 | 99.25% |
| Asian | 3 | 0.75% |
Married
Widowed
Divorced
Separated
Never Married
Petroleum County's average per capita income is $40,000. Household income levels show a median of $59,318. The poverty rate stands at 6.48%.
Name | Median | Mean |
|---|---|---|
| Married Families | $81,875 | - |
| Families | $78,750 | $90,634 |
| Households | $59,318 | $79,305 |
| Non Families | $33,750 | $59,164 |
Average Income
Median Household Income
Poverty Rate
