County annual report · FIPS 30003
2025 Big Horn County, MT Power Outage Report
In 2025, customers in Big Horn County, MT went without power for an average of 1.7 hours, a total of 11K customer-hours (Montana average 6.8 hours). That ranks 41st worst of 51 Montana counties and 2548th 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 Big Horn 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 | April 17, 2025 09:45 | April 20, 2025 03:15 | 2d 17h | 1,779 | 8,478 |
| 2 | June 12, 2025 02:00 | June 12, 2025 03:45 | 1h 45m | 304 | 359 |
| 3 | November 13, 2025 20:00 | November 14, 2025 01:30 | 5h 30m | 129 | 566 |
| 4 | June 14, 2025 01:30 | June 14, 2025 11:45 | 10h 15m | 103 | 771 |
| 5 | May 1, 2025 19:00 | May 1, 2025 21:45 | 2h 45m | 96 | 260 |
| 6 | December 20, 2025 00:45 | December 20, 2025 02:15 | 1h 30m | 41 | 62 |
| 7 | March 18, 2025 12:45 | March 18, 2025 13:00 | 15m | 39 | 10 |
| 8 | June 8, 2025 20:30 | June 9, 2025 18:00 | 21h 30m | 32 | 177 |
| 9 | December 17, 2025 23:45 | December 18, 2025 03:00 | 3h 15m | 32 | 58 |
| 10 | June 16, 2025 02:45 | June 16, 2025 04:45 | 2h | 30 | 60 |
Outage episodes by size in 2025: 4 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 Big Horn 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 |
|---|---|---|---|---|---|
| NorthWestern Energy LLC - (MT) | 2024 | 3.9 hrs | 1.30 | 2.0 hrs | 0.95 |
| Powder River Energy Corp | 2024 | 8.3 hrs | 2.88 | 4.9 hrs | 2.24 |
| Big Horn Rural Electric Co | 2018 | 4.0 hrs | 1.80 | - | - |
| Mid-Yellowstone Elec Coop, Inc | 2018 | 4.5 hrs | 3.82 | 4.5 hrs | 3.82 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Tongue River Electric Coop Inc | - | - | - | - | - |
| Yellowstone Valley Elec Co-op | - | - | - | - | - |
| Big Horn County Elec 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 ÷ 6,865 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. Big Horn County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Big Horn 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/big-horn-county