County annual report · FIPS 30087
2021 Rosebud County, MT Power Outage Report
In 2021, customers in Rosebud County, MT went without power for an average of 5.8 hours, a total of 27K customer-hours (Montana average 5.0 hours). That ranks 23rd worst of 51 Montana counties and 1182nd of 2,974 nationally.
Compared with MT, the US and 2020
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Rosebud County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | November 2, 2021 06:00 | November 2, 2021 07:00 | 1h | 1,182 | 1,181 |
| 2 | January 13, 2021 22:30 | January 14, 2021 04:15 | 5h 45m | 1,172 | 1,781 |
| 3 | February 23, 2021 04:30 | February 23, 2021 06:30 | 2h | 1,168 | 1,480 |
| 4 | October 12, 2021 15:30 | October 12, 2021 19:15 | 3h 45m | 1,157 | 1,151 |
| 5 | April 26, 2021 10:00 | April 26, 2021 10:15 | 15m | 1,154 | 289 |
| 6 | September 24, 2021 06:00 | September 24, 2021 10:15 | 4h 15m | 1,152 | 4,344 |
| 7 | May 6, 2021 06:15 | May 6, 2021 08:00 | 1h 45m | 1,085 | 1,897 |
| 8 | May 26, 2021 06:15 | May 26, 2021 08:00 | 1h 45m | 1,075 | 1,367 |
| 9 | May 6, 2021 16:00 | May 6, 2021 16:45 | 45m | 1,065 | 793 |
| 10 | March 29, 2021 15:00 | March 29, 2021 19:15 | 4h 15m | 481 | 1,552 |
Outage episodes by size in 2021: 20 reached 100+ customers, 9 reached 1,000+ customers, 0 reached 10,000+ customers.
Utility reliability filed with the EIA
SAIDI (average outage time per customer) and SAIFI (average interruptions per customer) that utilities serving Rosebud County reported on EIA Form 861 for 2021, or their most recent earlier filing. Utility-wide figures, not county-specific.
| Utility | EIA year | SAIDI | SAIFI | SAIDI excl. major events | SAIFI excl. major events |
|---|---|---|---|---|---|
| NorthWestern Energy LLC - (MT) | 2021 | 2.5 hrs | 1.37 | 2.1 hrs | 1.18 |
| Mid-Yellowstone Elec Coop, Inc | 2018 | 4.5 hrs | 3.82 | 4.5 hrs | 3.82 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Montana-Dakota Utilities Co | - | - | - | - | - |
| McCone Electric Coop Inc | - | - | - | - | - |
| Tongue River Electric Coop Inc | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 76% of Montana's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 4,647 customers (ORNL modeled county customer count), including major storm days. It is comparable across counties but is not the SAIDI a utility files.
- An outage event is a continuous stretch with customers out; counts at 100, 1,000 and 10,000+ use its peak.
- Years loaded: 2015–2025. Rosebud County has data for 2017–2025.
Cite this report
MassOutage (massoutage.com), Rosebud County, MT annual power outage report, 2021, data as of Oct 3, 2026 02:41 UTC, sources: DOE EAGLE-I (https://eagle-i.doe.gov/); EAGLE-I modeled customer counts (MCC) (https://figshare.com/); EIA Form 861 (utility reliability) (https://www.eia.gov/electricity/data/eia861/). https://massoutage.com/reports/2021/montana/rosebud-county