County annual report · FIPS 30051
2021 Liberty County, MT Power Outage Report
In 2021, customers in Liberty County, MT went without power for an average of 7.2 hours, a total of 5,787 customer-hours (Montana average 5.0 hours). That ranks 21st worst of 51 Montana counties and 1013th 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 Liberty 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 17:00 | January 14, 2021 03:45 | 10h 45m | 841 | 2,667 |
| 2 | July 11, 2021 23:45 | July 12, 2021 17:30 | 17h 45m | 821 | 934 |
| 3 | July 20, 2021 19:00 | July 21, 2021 00:30 | 5h 30m | 309 | 1,022 |
| 4 | February 22, 2021 04:00 | February 22, 2021 06:45 | 2h 45m | 158 | 435 |
| 5 | November 17, 2021 01:00 | November 17, 2021 04:00 | 3h | 119 | 211 |
| 6 | April 12, 2021 13:30 | April 12, 2021 16:00 | 2h 30m | 45 | 72 |
| 7 | April 25, 2021 16:30 | April 25, 2021 19:15 | 2h 45m | 16 | 32 |
| 8 | May 26, 2021 20:30 | May 27, 2021 00:30 | 4h | 16 | 49 |
| 9 | November 27, 2021 15:00 | November 27, 2021 16:30 | 1h 30m | 16 | 24 |
| 10 | January 16, 2021 21:15 | January 17, 2021 00:15 | 3h | 14 | 22 |
Outage episodes by size in 2021: 5 reached 100+ customers, 0 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 Liberty 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 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Sun River Electric Coop, Inc | - | - | - | - | - |
| Hill County Electric Coop, Inc | - | - | - | - | - |
| Marias 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 ÷ 804 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. Liberty County has data for 2020–2025.
Cite this report
MassOutage (massoutage.com), Liberty 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/liberty-county