County annual report · FIPS 30017
2020 Custer County, MT Power Outage Report
In 2020, customers in Custer County, MT went without power for an average of 2.2 hours, a total of 15K customer-hours (Montana average 5.6 hours). That ranks 40th worst of 50 Montana counties and 2181st of 3,019 nationally.
Compared with MT, the US and 2019
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Custer County, 2020
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | December 3, 2020 09:15 | December 3, 2020 13:00 | 3h 45m | 4,487 | 4,519 |
| 2 | August 20, 2020 19:30 | August 20, 2020 22:00 | 2h 30m | 1,689 | 3,186 |
| 3 | September 1, 2020 09:00 | September 1, 2020 10:00 | 1h | 916 | 238 |
| 4 | August 20, 2020 04:00 | August 20, 2020 05:00 | 1h | 902 | 282 |
| 5 | August 19, 2020 15:30 | August 19, 2020 16:45 | 1h 15m | 881 | 758 |
| 6 | March 4, 2020 18:45 | March 4, 2020 22:15 | 3h 30m | 873 | 583 |
| 7 | May 21, 2020 00:15 | May 21, 2020 04:00 | 3h 45m | 835 | 875 |
| 8 | July 4, 2020 16:45 | July 4, 2020 18:30 | 1h 45m | 795 | 261 |
| 9 | September 2, 2020 21:15 | September 2, 2020 22:45 | 1h 30m | 778 | 253 |
| 10 | September 2, 2020 23:30 | September 3, 2020 00:00 | 30m | 545 | 273 |
Outage episodes by size in 2020: 16 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 Custer County reported on EIA Form 861 for 2020, 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 |
|---|---|---|---|---|---|
| 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 | - | - | - | - | - |
| Southeast 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 2020; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 6,942 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. Custer County has data for 2017–2025.
Cite this report
MassOutage (massoutage.com), Custer County, MT annual power outage report, 2020, 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/2020/montana/custer-county