Petroleum County, Montana: Power, Data Centers and the Local Economy
No data center or power plant project is on record in Petroleum County, but the national build-out still reaches it through its utility bill, its labor market and the projects next door. Petroleum County is home to Winnett. Employers here counted 104 jobs in 2025, up 18.2% from 2019 (the 7th fastest growth of 56 Montana counties). Next door, Rosebud County has 1 data center. 548 people live here, up 9.2% since 2020. Unemployment was 3.7% in August 2026, against 4.2% in 2019.
Cities and towns in Petroleum County
Petroleum County is home to Winnett.
Residents are 2025 Census estimates for the part of each city, town or township inside this county. Census publishes no annual estimate for unincorporated communities.
What changed in Petroleum County
1st = the most. Ranks cover counties with a value on record.
| Measure | Then | Now | Change | Rank in Montana |
|---|---|---|---|---|
| Population (2020 → 2025) | 502 | 548 | ▲ 9.2% | 56th of 56 by size |
| Total jobs (2019 → 2025) | 88 | 104 | ▲ 18.2% | 7th of 56 by growth |
| Average annual pay (2019 → 2025) | $29,430 | $36,848 | ▲ 25.2% | — |
| Unemployment rate (2019 → August 2026) | 4.2% | 3.7% | ▼ 0.5pts | — |
Fergus Electric Coop, Inc is the largest utility serving Petroleum County, one of 2 with territory here. Its residential customers paid an average 15.52¢/kWh in 2024, above the 10.95¢ median for Montana utilities.
Who powers Petroleum County
Utilities with service territory in Petroleum County
| Utility | Ownership | Service | Residential customers (systemwide) | Residential price, 2024 | Commercial share of sales |
|---|---|---|---|---|---|
| Fergus Electric Coop, Inc | Cooperative | Bundled | 6,682 | 15.52¢ | 74% |
| McCone Electric Coop Inc | — | — | — | — | — |
Customer counts, prices and sales shares cover each utility's whole system in the state, not only this county. Commercial sales include data centers.
No operating power plant is located in Petroleum County in the EIA-860M inventory. Its power comes over the grid from plants elsewhere.
The Petroleum County labor market
| Industry (2025) | Jobs | Average pay | Concentration vs U.S. |
|---|---|---|---|
| All industries | 104 | $36,848 | 1.00 |
Concentration is the BLS location quotient: 1.0 means the industry holds the same share of local jobs as it does nationally. Industry rows count private employers; cells BLS suppresses are left out.
Data centers and local rules in Petroleum County
No data center, local measure or delayed project is on record in Petroleum County. Montana has 5 local measures on record statewide.
Petroleum County and its neighbors
Of the 5 counties that border Petroleum County, Rosebud County carries the most build-out activity: data centers, planned generation and operating plants combined.
| County | Population | Jobs since 2019 | Operating MW | Planned MW | Data centers | Local measures |
|---|---|---|---|---|---|---|
| Petroleum County | 548 | ▲ 18.2% | — | — | — | — |
| Fergus County | 11,825 | ▼ 1.4% | — | — | — | — |
| Garfield County | 1,148 | ▲ 3.9% | — | — | — | — |
| Musselshell County | 5,582 | ▲ 4.0% | — | — | — | — |
| Phillips County | 4,203 | ▼ 2.0% | — | — | — | — |
| Rosebud County | 8,253 | ▼ 4.6% | 2,262 MW | — | 1 | — |
More of Montana
Petroleum County, answered from the record
Who provides electricity in Petroleum County, Montana?
2 utilities have service territory in Petroleum County in the EIA-861 2024 report: Fergus Electric Coop, Inc, McCone Electric Coop Inc. The largest, Fergus Electric Coop, Inc, charged residential customers 15.52¢/kWh on average in 2024.
Are there data centers in Petroleum County?
The SAVRN Data Center Map has no data center in Petroleum County. The nearest activity on record is next door in Rosebud County.
Is Petroleum County adding jobs?
Employers counted 104 jobs in 2025 against 88 in 2019 (+18.2%, BLS QCEW).
Does Petroleum County have a data center moratorium?
No county-level measure is on record for Petroleum County. Montana has 5 local measures statewide, listed on the state page.