Sully County, South Dakota: Power, Data Centers and the Local Economy
Home to Cow Creek
No data center or power plant project is on record in Sully County, but the national build-out still reaches it through its utility bill, its labor market and the projects next door. Sully County is home to Onida. Employers here counted 692 jobs in 2025, down 9.1% from 2019. Unemployment was 1.7% in August 2026, against 2.3% in 2019. Dakota Energy Coop Inc is the largest utility serving Sully County, one of 4 with territory here. Its residential customers paid an average 15.30¢/kWh in 2024, above the 12.48¢ median for South Dakota utilities. 1,479 people live here, up 1.9% since 2020.
Cities and towns in Sully County
Sully County is home to Onida.
Unincorporated communities (governed by the county): Cow Creek.
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 Sully County
1st = the most. Ranks cover counties with a value on record.
| Measure | Then | Now | Change | Rank in South Dakota |
|---|---|---|---|---|
| Population (2020 → 2025) | 1,451 | 1,479 | ▲ 1.9% | 62nd of 66 by size |
| Total jobs (2019 → 2025) | 761 | 692 | ▼ 9.1% | 64th of 66 by growth |
| Average annual pay (2019 → 2025) | $45,988 | $56,436 | ▲ 22.7% | — |
| Unemployment rate (2019 → August 2026) | 2.3% | 1.7% | ▼ 0.6pts | — |
Who powers Sully County
Utilities with service territory in Sully County
| Utility | Ownership | Service | Residential customers (systemwide) | Residential price, 2024 | Commercial share of sales |
|---|---|---|---|---|---|
| Dakota Energy Coop Inc | Cooperative | Bundled | 3,224 | 15.30¢ | 18% |
| Oahe Electric Coop Inc | — | — | — | — | — |
| City of Onida - (SD) | — | — | — | — | — |
| WAPA-- Western Area Power Administration | Federal | Bundled | — | — | 99% |
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 Sully County in the EIA-860M inventory. Its power comes over the grid from plants elsewhere.
The Sully County labor market
| Industry (2025) | Jobs | Average pay | Concentration vs U.S. |
|---|---|---|---|
| All industries | 692 | $56,436 | 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 Sully County
No data center, local measure or delayed project is on record in Sully County. South Dakota has 4 local measures on record statewide.
Sully County and its neighbors
Of the 5 counties that border Sully County, Hughes 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 |
|---|---|---|---|---|---|---|
| Sully County | 1,479 | ▼ 9.1% | — | — | — | — |
| Dewey County | 5,419 | ▲ 5.5% | — | — | — | — |
| Hughes County | 17,570 | ▲ 0.7% | 787 MW | — | — | — |
| Hyde County | 1,191 | ▼ 2.7% | 491 MW | — | — | — |
| Potter County | 2,377 | ▲ 2.2% | — | — | — | — |
| Stanley County | 3,018 | ▲ 12.8% | 6 MW | — | — | — |
More of South Dakota
Sully County, answered from the record
Who provides electricity in Sully County, South Dakota?
4 utilities have service territory in Sully County in the EIA-861 2024 report: Dakota Energy Coop Inc, Oahe Electric Coop Inc, City of Onida - (SD), WAPA-- Western Area Power Administration. The largest, Dakota Energy Coop Inc, charged residential customers 15.30¢/kWh on average in 2024.
Are there data centers in Sully County?
The SAVRN Data Center Map has no data center in Sully County.
Is Sully County adding jobs?
Employers counted 692 jobs in 2025 against 761 in 2019 (-9.1%, BLS QCEW).
Does Sully County have a data center moratorium?
No county-level measure is on record for Sully County. South Dakota has 4 local measures statewide, listed on the state page.