County annual report · FIPS 30017
2025 Custer County, MT Power Outage Report
In 2025, customers in Custer County, MT went without power for an average of 0.4 hours, a total of 2,715 customer-hours (Montana average 6.8 hours). That ranks 44th worst of 51 Montana counties and 2893rd of 3,000 nationally.
Compared with MT, the US and 2024
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Custer County, 2025
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 20, 2025 17:45 | February 20, 2025 18:00 | 15m | 1,486 | 372 |
| 2 | May 16, 2025 06:00 | May 16, 2025 13:15 | 7h 15m | 310 | 179 |
| 3 | June 9, 2025 02:00 | June 9, 2025 03:15 | 1h 15m | 129 | 161 |
| 4 | June 16, 2025 04:15 | June 16, 2025 08:30 | 4h 15m | 127 | 228 |
| 5 | August 15, 2025 01:15 | August 15, 2025 02:15 | 1h | 121 | 112 |
| 6 | September 8, 2025 15:15 | September 8, 2025 15:45 | 30m | 115 | 57 |
| 7 | August 17, 2025 14:00 | August 17, 2025 15:15 | 1h 15m | 107 | 134 |
| 8 | September 17, 2025 20:15 | September 18, 2025 00:30 | 4h 15m | 86 | 116 |
| 9 | May 2, 2025 22:15 | May 3, 2025 01:15 | 3h | 68 | 148 |
| 10 | July 18, 2025 05:15 | July 18, 2025 07:15 | 2h | 67 | 33 |
Outage episodes by size in 2025: 7 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 Custer County reported on EIA Form 861 for 2025, 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 |
|---|---|---|---|---|---|
| Montana-Dakota Utilities Co | 2024 | 2.9 hrs | 1.26 | 2.1 hrs | 1.10 |
| Mid-Yellowstone Elec Coop, Inc | 2018 | 4.5 hrs | 3.82 | 4.5 hrs | 3.82 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| 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 n/a of Montana's customers in 2025; 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, 2025, 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/2025/montana/custer-county