In the midst of significant Wyoming power outages, thousands of residents and businesses lost electricity across central and northeastern Wyoming on the afternoon of November 13, 2025. As of this evening, utilities report partial restoration—but many customers remain without service while investigations into the root cause continue.
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Major Outage Event & Immediate Cause
The disruption began at approximately 12:45 p.m. MST when two 500-kilovolt transmission lines near Medicine Bow, Wyoming tripped, triggering an abnormal voltage event that cascaded through interconnected lines. Wyoming Public Media+2WyoFile+2
From there, multiple lines including those managed by the federal Western Area Power Administration (WAPA) were automatically disconnected, spreading outages across the region. Wyoming Public Media+1
Scope and Impact of the Outages
- At the peak, as many as 95,000 customers in Wyoming were reported to be without power. WyoFile+1
- Utility Rocky Mountain Power (RMP) stated that roughly 56,776 customers lost power around 2 p.m. in central and northeast Wyoming. WyoFile
- Rural utility Powder River Energy Corporation (PRECorp), serving five counties in northeast Wyoming, reported that 26,544 customers experienced outages. WyoFile
- According to live-tracker data around the evening, about 12,287 homes and businesses remained without power in Wyoming (~2.8% of the tracked 437,527 customers statewide). PowerOutage.us
Affected Areas & Utilities
Highly impacted counties and utilities include:
- Campbell County – over 3,500 customers out; ~28.7% outage rate for tracked customers. PowerOutage.us+1
- Crook County – ~3,389 customers out; ~51% of tracked customers. PowerOutage.us
- Weston County – ~3,060 customers out; ~55.8% outage rate. PowerOutage.us
- Cities and towns such as Cody, Gillette, Sheridan, Douglas and major rural co-op service zones were all affected. WyoFile+1
- Also impacted: Adjacent states. For instance, parts of western South Dakota saw outages tied to the same transmission event. https://www.kotatv.com+1
Utility Response & Restoration Status
- RMP indicated that although crews are working “diligently to safely restore power,” the distance and complexity of the restoration process mean it could take several hours. Wyoming Public Media
- By 6 p.m., the number of affected customers had been reduced significantly—from about 93,000 at the peak to around 16,000 remaining. Cowboy State Daily
- PRECorp warned its members that the voltage instability in their system could lead to extended outages “through the night,” urging caution with generator use and erratic supply. Wyoming Public Media
Safety Considerations & Emergency Measures
- Residents were advised to treat all downed power lines as live and not to touch them—this standard safety message is underlined by the transmission event. WyoFile
- In Casper/Natrona County, locations were set up for residents dependent on medical devices to charge and seek support: e.g., at the Memorial Hospital of Converse County (Douglas) and Glenrock Police Department. Wyoming Public Media
- The outage knocked out traffic signals in some towns—local authorities urged drivers to treat dark intersections as four-way stops to reduce risk. Cowboy State Daily
- Emergency services requested that the public reserve 911 calls for true emergencies so lines remain open for urgent needs. https://www.kotatv.com
What’s Causing the Disruption & What’s Being Investigated
- The initial incident: Two major 500 kV relay lines near Medicine Bow tripped, creating a cascading outage. WyoFile+1
- The federal agency WAPA described this as a kind of “abnormal voltage event” which caused further transmission lines to trip. Wyoming Public Media
- Meanwhile, a fire at the coal-fired Dave Johnston Power Plant near Glenrock occurred—but authorities clarified it happened after the outages began and was likely a consequence, not the initial cause. Cowboy State Daily+1
- The investigations remain ongoing. Utilities are coordinating to determine what specifically triggered the line trips and how grid resiliency was impacted. Wyoming Public Media
What Homeowners & Residents Should Know
- If you still have no power in your area, check your utility’s outage map and alerts—that will give you the most timely information. For example, RMP’s outage map and text service (“OUT” to 759677) remain active. Wyoming Public Media
- Prepare for intermittent power or “lights on/lights off” scenarios while grid voltages stabilize—rushing restoration too fast risks equipment damage. Wyoming Public Media
- Use caution if running a backup generator: ensure proper ventilation and safe wiring, and be aware that traffic signals might be out.
- Help keep emergency lines clear: avoid calling 911 unless there is immediate danger, especially during large-scale outage events.
- Stay informed via official utility social media, county emergency management alerts, and trusted news outlets.
Looking Ahead: Restoration & Resilience
Utility crews are working around the clock to restore full service. While many customers have already seen power return, the scale and nature of the grid disturbance suggest it may take until late tonight for full normalization. Cowboy State Daily
Moving forward, this event will likely prompt additional review of Wyoming’s transmission system resilience, inter-utility coordination, and backup capacity for critical infrastructure (hospitals, generators, emergency services). The state’s emergency management offices are monitoring for any ripple effects.
Stay updated on your local outage map, follow utility statements, and take necessary safety precautions as the state works to recover from today’s wide-scale Wyoming power outages.
