County annual report · FIPS 30017
2018 Custer County, MT Power Outage Report
In 2018, customers in Custer County, MT went without power for an average of 0.4 hours, a total of 2,606 customer-hours (Montana average 1.9 hours). That ranks 13th worst of 20 Montana counties and 2563rd of 2,798 nationally.
Compared with MT, the US and 2017
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Custer County, 2018
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | February 10, 2018 13:45 | February 10, 2018 17:30 | 3h 45m | 969 | 1,135 |
| 2 | July 2, 2018 01:45 | July 2, 2018 02:30 | 45m | 579 | 283 |
| 3 | February 10, 2018 23:45 | February 11, 2018 01:00 | 1h 15m | 272 | 276 |
| 4 | June 22, 2018 04:00 | June 22, 2018 05:45 | 1h 45m | 247 | 424 |
| 5 | July 11, 2018 07:30 | July 11, 2018 08:00 | 30m | 173 | 45 |
| 6 | June 16, 2018 13:15 | June 16, 2018 13:30 | 15m | 53 | 13 |
| 7 | July 1, 2018 15:00 | July 1, 2018 15:15 | 15m | 37 | 9 |
| 8 | August 3, 2018 02:15 | August 3, 2018 02:45 | 30m | 36 | 10 |
| 9 | June 9, 2018 04:00 | June 9, 2018 08:30 | 4h 30m | 31 | 56 |
| 10 | September 30, 2018 19:30 | September 30, 2018 20:15 | 45m | 29 | 22 |
Outage episodes by size in 2018: 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 Custer County reported on EIA Form 861 for 2018, 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 16% of Montana's customers in 2018; 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, 2018, 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/2018/montana/custer-county