Regional blackout — Outage affects thousands across Wyoming and South Dakota
A massive regional power outage swept across the area Thursday, cutting electricity to more than 100,000 customers at its peak, disrupting local services and prompting a coordinated response from utilities and emergency agencies.
The outage began around 12:45 p.m. Nov. 13, according to Weston County Homeland Security Coordinator Gilbert Nelson. It was later tied to problems on a 500-kilovolt transmission line near Medicine Bow, according to a release from Powder River Energy Corp.
The disruption cascaded across multiple states, temporarily knocking power offline for customers of Black Hills Energy, PRECorp and several other utilities.
Impact in Weston County
Weston County Emergency Management reported that the outage was “massive,” stretching well beyond the county and state, Nelson said. Local agencies — including the Upton Volunteer Fire Department, Weston County Health Services and Weston County School District No. 1 — contacted emergency officials as they assessed potential impacts.
Nelson noted that resources began mobilizing and Weston County Health Services was asked to prepare for a possible influx of patients if the outage persisted.
“Thankfully this didn’t last long, and power was back on within a short amount of time,” Nelson said, although Black Hills Energy and PRECorp later reported that some customers experienced extended outages.
A second brief outage occurred around 2:20 p.m. as the grid continued to stabilize.
Due to the outage, Newcastle schools released early that day. A facebook post directed parents to pick up students in the normal fashion at all three schools.
Weight room and other school facilities were also closed for the evening and other scheduled activities were canceled.
Black Hills Energy: phased restoration
Black Hills Energy activated its emergency response plan early in the afternoon, emphasizing that customer safety remained its top priority.
By 2:30 p.m., the company reported that power had been restored to roughly half of affected customers in Wyoming and South Dakota. Crews began re-energizing circuits in phases to prevent system damage.
“The restoration process is complex as our power generation facilities and substations were impacted,” the company said. “We will use a phased process to restore power which balances system safety and stability.”
Black Hills Energy warned that customers could experience short, intermittent outages such as blinking lights during the stabilization period.
By Thursday evening, the utility estimated that most customers would have service restored by about 10 p.m. In its final advisory of the night, the company said nearly all customers had power back. Those experiencing partial service were encouraged to check for tripped breakers or ground-fault outlets.
PRECorp: unprecedented blackout
PRECorp, which serves more than 27,000 meters across northeast Wyoming and southern Montana, described the outage as unprecedented. The blackout affected every PRECorp service and shut down substations across Campbell, Crook, Johnson, Sheridan and Weston counties, according to the cooperative.
Line crews were dispatched to more than 30 substations to ensure that equipment could be safely re-energized.
“We wanted to have eyes on every substation before it was energized,” Vice President of Engineering Quentin Rogers said in the release. “We avoided some problems for sure.”
Restoration began around 3 p.m., with communities coming back online starting about 4:30 p.m. Full service was restored by approximately 9 p.m. Thursday.
“Although the sudden loss of electricity across an entire region came as a jolt to residents and businesses who operate here, the PRECorp systems that protect infrastructure and consumers performed as designed as it responded to the high and low voltage scenarios,” the release said. “At this time, no employees were injured during the response and restoration.”
Safety reminders
Black Hills Energy urged customers to follow safety precautions during outages, including:
• Keep refrigerator and freezer doors closed to preserve food.
• Use flashlights instead of candles to prevent fire hazards.
• Never use generators indoors or in enclosed spaces.
• Treat intersections with non-functioning traffic signals as four-way stops.