County annual report · FIPS 30089
2021 Sanders County, MT Power Outage Report
In 2021, customers in Sanders County, MT went without power for an average of 37.8 hours, a total of 277K customer-hours (Montana average 5.0 hours). That ranks 3rd worst of 51 Montana counties and 235th 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 Sanders 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 | January 13, 2021 13:15 | January 27, 2021 00:00 | 13d 10h | 7,428 | 232K |
| 2 | November 15, 2021 20:15 | November 18, 2021 23:30 | 3d 3h | 1,297 | 14K |
| 3 | June 9, 2021 19:30 | June 9, 2021 20:15 | 45m | 869 | 652 |
| 4 | April 19, 2021 00:30 | April 20, 2021 23:30 | 1d 23h | 830 | 8,375 |
| 5 | December 20, 2021 17:30 | December 20, 2021 21:15 | 3h 45m | 603 | 1,070 |
| 6 | June 30, 2021 00:00 | June 30, 2021 02:30 | 2h 30m | 472 | 962 |
| 7 | March 28, 2021 23:00 | March 29, 2021 15:00 | 16h | 450 | 2,559 |
| 8 | June 19, 2021 20:45 | June 19, 2021 23:00 | 2h 15m | 449 | 878 |
| 9 | August 2, 2021 05:15 | August 2, 2021 11:15 | 6h | 379 | 1,370 |
| 10 | February 26, 2021 03:15 | February 26, 2021 05:45 | 2h 30m | 358 | 812 |
Outage episodes by size in 2021: 29 reached 100+ customers, 2 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 Sanders 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 |
| Avista Corp | 2021 | 16.1 hrs | 2.31 | 2.9 hrs | 1.29 |
| Flathead Electric Coop Inc | 2021 | 11.2 hrs | 2.62 | 2.7 hrs | 1.97 |
| NorthWestern Energy | - | - | - | - | - |
| Northern Lights, Inc | - | - | - | - | - |
| USBIA-Mission Valley Power | - | - | - | - | - |
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 ÷ 7,314 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. Sanders County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Sanders 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/sanders-county