County annual report · FIPS 56033
2021 Sheridan County, WY Power Outage Report
In 2021, customers in Sheridan County, WY went without power for an average of 4.1 hours, a total of 72K customer-hours (Wyoming average 2.2 hours). That ranks 6th worst of 20 Wyoming counties and 1511th of 2,974 nationally.
Compared with WY, the US and 2020
Coverage line is EAGLE-I's share of Wyoming customers tracked each year.
Biggest outages in Sheridan 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 | October 12, 2021 08:45 | October 13, 2021 21:00 | 1d 12h | 2,784 | 28K |
| 2 | January 5, 2021 17:45 | January 5, 2021 23:30 | 5h 45m | 2,052 | 4,304 |
| 3 | August 19, 2021 05:00 | August 19, 2021 14:30 | 9h 30m | 1,346 | 8,365 |
| 4 | April 11, 2021 01:30 | April 11, 2021 05:15 | 3h 45m | 1,219 | 3,556 |
| 5 | December 1, 2021 19:45 | December 1, 2021 21:00 | 1h 15m | 664 | 240 |
| 6 | July 19, 2021 15:45 | July 19, 2021 17:00 | 1h 15m | 622 | 163 |
| 7 | August 30, 2021 23:15 | August 31, 2021 01:30 | 2h 15m | 590 | 1,265 |
| 8 | January 13, 2021 21:30 | January 14, 2021 06:15 | 8h 45m | 587 | 1,526 |
| 9 | July 12, 2021 17:15 | July 12, 2021 18:00 | 45m | 549 | 412 |
| 10 | February 13, 2021 13:45 | February 13, 2021 17:00 | 3h 15m | 543 | 1,170 |
Outage episodes by size in 2021: 39 reached 100+ customers, 4 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 Sheridan 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 |
|---|---|---|---|---|---|
| Powder River Energy Corp | 2021 | 5.4 hrs | 2.15 | 3.9 hrs | 1.91 |
| Big Horn Rural Electric Co | 2018 | 4.0 hrs | 1.80 | - | - |
| Montana-Dakota Utilities Co | - | - | - | - | - |
| 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 71% of Wyoming's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 17,618 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. Sheridan County has data for 2017–2025.
Cite this report
MassOutage (massoutage.com), Sheridan County, WY 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/wyoming/sheridan-county