Editor’s Note: This is a developing story and may be updated.
Updated at 5:30 p.m. on Nov. 13, 2025
Thursday’s massive power outages that affected much of central and northeastern Wyoming, along with parts of South Dakota, were likely due to two tripped lines near Medicine Bow.
“We are aware of power outages affecting portions of Wyoming, including the central area of the state in and around Casper, as well as western South Dakota. We believe the outage, which began around 12:45 p.m. MST, was triggered by two tripped 500-kilovolt lines near Medicine Bow, Wyoming. This incident resulted in an abnormal voltage event that subsequently tripped a number of surrounding lines, including WAPA transmission, resulting in further power outages to communities across the area. We are coordinating with a number of major utilities in the area as well as other WAPA customers to address the outage as quickly as possible,” Stephen Collier, public affairs specialist with Western Area Power Administration (WAPA), said in an emailed statement.
WAPA is a federal agency under the Department of Energy that markets and delivers reliable, hydroelectric power and transmission services. It manages and maintains a 15-state, high-voltage transmission network serving more than 680 utility customers.
“We understand the significant impact of this outage and are committed to restoring service as quickly and safely as possible. We will continue to gather information and provide updates as they become available. We appreciate the patience and understanding of all affected residents and businesses as we work to restore power,” Collier said.
Two areas have been opened for those in Converse County who are affected by the outage and need to charge their portable medical devices. Folks in Douglas can charge their devices in the waiting room at Memorial Hospital of Converse County. In Glenrock, you can go to the Glenrock Police Department.
The City of Casper has closed its emergency areas.
Updated at 4:30 p.m. on Nov. 13, 2025
Rural electric co-ops are updating members on power outages and what to expect through the night.
Powder River Energy Corporation (PRECorp), which serves five counties in northeast Wyoming, said in a Facebook post that its members should be “prepared for an extended outage through the night.”
PRECorp added that “the voltages coming into our system are unstable and are tripping off power. That’s why some are seeing ‘lights on, lights off.’ We have crews staged at almost every substation to begin safe restoration of power once the voltages stabilize. However, we do not want to flip the switches unsafely. We do not want to blow up transformers or arrestors and cause more problems.”
The Niobrara Electric Association (NEA) said it’s aware of the system wide outage and that its Lusk office is out of power, too. In a later Facebook post, the co-op said it is “due to transmission interruption from our power supplier.” NEA said it’s working to bring power back online.
At 3:35 p.m., Wyrulec Company in southeastern Wyoming shared on Facebook that all power had been restored to all Wyrulec members affected by the outage. It had affected services around Fort Laramie, Hartville and Guernsey.
High Plains Power hasn’t updated its Facebook outage post since 2:52 p.m.
No other electric co-ops in the state have posted about the outage.
Rocky Mountain Power issued a press release at 4 p.m., which said: “At 12:40 p.m. MT a widespread power outage occurred impacting more than 60,000 customers in Wyoming. The cause is currently under investigation. Our crews are working diligently to safely restore power as quickly as possible; however, due to the distance and complexity of the restoration process may take several hours. Customers can find the latest updates at RockyMountainPower.net/Outages.”
Updated at 3:30 p.m. on Nov. 13, 2025
Converse County Emergency Management Coordinator Russ Dalgarn confirmed that the Dave Johnston Power Plant in Glenrock caught fire on Thursday, but hadn’t been able to confirm with RMP whether the fire was related to the power outages.
He said the plant contacted outside resources, which assisted and put the fire out quickly.
Meanwhile, the Steamboat Gas Plant outside of Douglas is putting off a lot of black smoke because power to that plant is also down. This is separate from the fire at the Dave Johnston plant and is not an emergency.
The Natrona County Sheriff’s Office shared on Facebook two locations for individuals who are oxygen dependent to go during the outage.
High Plains Power is also reporting power is down in Fremont County and surrounding areas.
Originally posted at 2:56 p.m. on Nov. 13, 2025
Tens of thousands of Wyomingites lost power Thursday due to widespread outages that crossed state lines into South Dakota, according to a map from Power Outage.
Some 55,000 Rocky Mountain Power (RMP) customers in the central and northeast parts of the state lost their power, according to the company’s outage map.
“We’re aware of a power outage affecting approximately 40,744 customers in Casper, WY and surrounding areas,” the company posted to Facebook around 2:30 p.m. “The cause is under investigation. Crews are working to restore power as safely and quickly as possible. For updates, please text OUT to 759677 or visit rockymountainpower.net/outage.”
Wyoming Public Radio has a request for information out to RMP and will update this story when the company responds.
Meanwhile, Black Hills Energy posted around 1:40 p.m.: “We are responding to a large-scale regional electrical outage in South Dakota and Wyoming caused by a transmission facility located outside of our system. We have activated our response plan, and our personnel are well-trained to respond to events of this type. Safety is and will continue to be the company’s top priority. We will provide more information as soon as it is available.”
Hundreds of Black Hills customers in northeastern Wyoming and South Dakota were affected, according to the company’s outage map.
The company started re-energizing its system in segments starting around 2:30 p.m. and reported about half of its impacted customers have had their power restored. “We will continue to safely restore power to our customers this afternoon and potentially into the evening hours,” it said.
Natrona County Fire District also posted about the outage.
“Major power outage reported across Casper and Natrona County. Do not inundate 911 with calls, alarms will be activating. Please be patient at this time. More information to be provided at a later time. Thank you for your cooperation,” the post reads on Facebook.
A previous version of the post said the Glenrock Volunteer Fire Department was en route at the request of the Dave Johnston Power Plant in Glenrock, owned by RMP’s parent company PacifiCorp, indicating a fire at the plant may have caused the outage. That post was later removed.
Oil City News is reporting: “A person who answered a phone call to the plant said they were unable to comment and were unable to transfer calls from their outside position. Oil City News has reached out to PacifiCorp for information, and an Oil City News reporter at the scene has not witnessed any unusual activity in the area.”
Some customers were reporting power had been restored by midafternoon Thursday, while others continue to see their power turning off and on. Emergency services are asking people to only call 911 in an emergency, not because of the power outage.
