County annual report · FIPS 30095
2021 Stillwater County, MT Power Outage Report
In 2021, customers in Stillwater County, MT went without power for an average of 1.7 hours, a total of 9,160 customer-hours (Montana average 5.0 hours). That ranks 36th worst of 51 Montana counties and 2359th 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 Stillwater 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 | March 29, 2021 09:00 | March 29, 2021 20:45 | 11h 45m | 1,338 | 2,963 |
| 2 | February 11, 2021 09:30 | February 11, 2021 16:45 | 7h 15m | 500 | 3,500 |
| 3 | January 10, 2021 23:00 | January 11, 2021 00:00 | 1h | 103 | 103 |
| 4 | January 13, 2021 19:45 | January 14, 2021 20:00 | 1d | 92 | 1,648 |
| 5 | January 22, 2021 00:30 | January 22, 2021 02:15 | 1h 45m | 52 | 91 |
| 6 | December 27, 2021 17:45 | December 28, 2021 00:15 | 6h 30m | 34 | 156 |
| 7 | March 20, 2021 16:45 | March 20, 2021 22:00 | 5h 15m | 33 | 79 |
| 8 | November 24, 2021 18:15 | November 24, 2021 23:45 | 5h 30m | 29 | 152 |
| 9 | February 5, 2021 21:00 | February 6, 2021 00:45 | 3h 45m | 28 | 42 |
| 10 | February 22, 2021 03:30 | February 22, 2021 07:30 | 4h | 26 | 35 |
Outage episodes by size in 2021: 3 reached 100+ customers, 1 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 Stillwater 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 |
| NorthWestern Energy | - | - | - | - | - |
| Fergus Electric Coop, Inc | - | - | - | - | - |
| Yellowstone Valley Elec Co-op | - | - | - | - | - |
| Beartooth 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 ÷ 5,383 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. Stillwater County has data for 2020–2025.
Cite this report
MassOutage (massoutage.com), Stillwater 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/stillwater-county