Petroleum County, Montana: Farm Belt county. In 2024, voted R+76%. Republican peak: R+77 in 2016.
Key facts
- 2024 presidential margin
- R+76MIT Election Lab
- Political typology
- Farm BeltAkashic typology
- Population
- 4472024 5-year
- Median household income
- $60,2082024 5-year
- White (non-Hispanic)
- 98.9%2024 5-year
- Black
- 0.0%2024 5-year
- Hispanic / Latino
- 0.0%2024 5-year
- Peak Democratic margin
- D+33 in 1936MIT Election Lab
- Peak Republican margin
- R+77 in 2016MIT Election Lab
- Most similar
- Fergus County, MT · similarity 1.00
2024 results by precinct
2024 precinct map of Petroleum CountyPrecinct-level 2024 presidential results for Petroleum County, with each precinct boundary colored by Democratic-vs-Republican margin.
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Margin—
Turnout—
Harris +50Trump +50
Real precinct boundaries. Hover for vote totals.
presidential history
Presidential margin, 1876–2024
Democratic minus Republican, by election
| Year | Margin (D minus R) |
|---|---|
| 1876 | No data |
| 1880 | No data |
| 1884 | No data |
| 1888 | No data |
| 1892 | No data |
| 1896 | No data |
| 1900 | No data |
| 1904 | No data |
| 1908 | No data |
| 1912 | No data |
| 1916 | No data |
| 1920 | No data |
| 1924 | No data |
| 1928 | −22.2% |
| 1932 | +20.9% |
| 1936 | +32.9% |
| 1940 | +0.5% |
| 1944 | −5.8% |
| 1948 | +4.6% |
| 1952 | −34.6% |
| 1956 | −11.4% |
| 1960 | −7.1% |
| 1964 | +5.0% |
| 1968 | −33.7% |
| 1972 | −44.6% |
| 1976 | −30.5% |
| 1980 | −39.6% |
| 1984 | −49.6% |
| 1988 | −37.4% |
| 1992 | −25.0% |
| 1996 | −42.8% |
| 2000 | −71.2% |
| 2004 | −59.2% |
| 2008 | −53.0% |
| 2012 | −64.1% |
| 2016 | −77.0% |
| 2020 | −74.4% |
| 2024 | −76.2% |
DemocraticRepublican
38 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| R | 37 | 284 | 324 | ||
| R | 39 | 298 | 348 | ||
| R | 30 | 278 | 322 | ||
| R | 49 | 240 | 298 | ||
| R | 68 | 227 | 300 | ||
| R | 55 | 228 | 292 | ||
| R | 36 | 254 | 306 | ||
| R | 62 | 186 | 290 | ||
| R | 61 | 135 | 296 | ||
| R | 91 | 204 | 302 | ||
| R | 86 | 258 | 347 | ||
| R | 90 | 225 | 341 | ||
| R | 110 | 211 | 331 | ||
| R | 87 | 232 | 325 | ||
| R | 98 | 211 | 335 | ||
| D | 210 | 190 | 401 | ||
| R | 221 | 255 | 476 | ||
| R | 205 | 258 | 463 | ||
| R | 155 | 319 | 474 | ||
| D | 235 | 214 | 461 | ||
| R | 225 | 253 | 481 | ||
| D | 316 | 313 | 631 | ||
| D | 523 | 258 | 806 | ||
| D | 544 | 351 | 924 | ||
| R | 372 | 586 | 963 | ||
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Demographics
2024 ACS
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
German
34.7%
American
19.7%
English
17.9%
Irish
11.2%
Polish
2.2%
Scottish
2.0%
French
1.3%
Sample size too small to break out by ancestry reliably.
Multiple ancestry combinations reported; no single grouping above 1%.
Sample size too small to break out by ancestry reliably.
Sample size too small to break out by ancestry reliably.
American Indian, Alaska Native, Native Hawaiian, and Pacific Islander combined.
Source · American Community Survey 5-year estimates, 2024 release. Hispanic/Latino is an ethnicity that overlaps the race categories, so these shares can total more than 100%. Ancestry is a self-reported, multiple-response item; ancestry percentages do not sum to the parent race percentage.
2024 ACS
Age distribution by sex
Median age: 51.6 in this county, 39.1 nationally
Male
Age
Female
85+
75–84
65–74
55–64
45–54
35–44
25–34
18–24
5–17
<5
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Median household income
Inflation-adjusted dollars
$60,208
Petroleum County ranks near the middle of US counties.
Petroleum County$60,208
Montana$72,509
United States$80,734
Petroleum County ranks near the middle of US counties by median household income.
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Poverty rate
All persons below federal poverty line
8.1%
Child poverty is below the national average.
Children under 183.0%
Working age (18–64)9.4%
Seniors (65+)5.9%
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Language at home
Population aged 5 and older
100.0%
speak English only
Source · ACS 5-year estimates, 2024.
2020 religion census
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 92.6% of residents not counted as adherents by any reporting body.
With fewer than 500 residents spread across high-plains ranch land, Petroleum County consistently posts some of the most lopsided Republican margins in the nation — the 2024 gap of 76 points reflects both its demographic uniformity and extreme rural isolation.
The Republican margin here reached seventy-seven points in 2016. Between 2020 and 2024 the county moved two points toward the Republican candidate; the 2024 margin was seventy-six points.
A population of 447, a 99% non-Hispanic-white share, and a median household income of $60,208 describe an agricultural county. The county's voting pattern over the last decade is most similar to that of Fergus County and Blanco County.
Most similar counties
Compare two places, side by side
Twelve curated comparisons line up election history, demographics, and the divergence story for two places at a glance. Browse all comparisons →
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
Petroleum County, Montana. Akashic. https://akashic.app/county/30069/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
More in Montana
More farm belt counties
Frequently asked questions
How did Petroleum County, Montana vote in 2024?
In 2024, Petroleum County, Montana voted Republican by 76.2 points (R+76), carried by the Republican candidate. Out of 324 votes cast, 37 went Democratic and 284 went Republican.
What is Petroleum County, Montana's political typology?
Akashic places Petroleum County, Montana in the "Farm Belt" typology — Rural Plains and Midwest farm counties — Republican, with modest recent movement. The typology is a data-driven cluster built from vote share, vote swing, race and ethnicity, income, language spoken at home, religion, and ancestry. Across 38 elections in the dataset, the county has voted Democratic 5 times, Republican 20 times, and other 0 times.
When did Petroleum County, Montana last vote Democratic?
The most recent presidential election in which Petroleum County, Montana voted Democratic was 1964.
How many people live in Petroleum County, Montana?
Petroleum County, Montana has a population of 447 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Petroleum County, Montana?
Median household income in Petroleum County, Montana is $60,208 — below the national median of $80,734. The Montana state median is $72,509.
What is the political history of Petroleum County, Montana?
Akashic tracks 38 presidential elections in Petroleum County, Montana from 1876 to 2024. Of those, 5 went Democratic and 20 went Republican. The county's typology — "Farm Belt" — captures where that record, its demographics, and its recent swing place it among American communities.