LITTLE ROCK, Ark. — Southwest Power Pool (SPP) today celebrates the successful expansion of its service territory into the Western Interconnection of the nation’s power grid. The milestone makes SPP the first regional transmission organization (RTO) with services spanning two interconnections, positioning its member organizations to reap benefits from an operationally and geographically diverse integrated system.

Following months of intensive testing, simulation, and joint operational coordination with dozens of participating utilities, SPP’s expanded RTO operations officially began at midnight central time on April 1.

Nine load-serving utilities led the expansion, which extends SPP’s service territory to include resources and customers of numerous utilities in seven states – Arizona, Colorado, Montana, Nebraska, New Mexico, Utah, and Wyoming. As RTO members and participants in SPP’s wholesale market, they will gain access to the RTO’s vast portfolio of generating resources, innovative planning services, and support in coordinating electric reliability. (A list of the entities participating in this effort and a map of the expanded SPP region are included as an below, along with statements by leaders of organizations joining or expanding their participation in the RTO on April 1.)

“SPP’s western expansion is a landmark milestone for our organization, our new members, and the broader energy industry,” said SPP President and CEO Lanny Nickell. “This is one of many bold steps we’re taking to deliver long-term value to more consumers.”

Participation in SPP’s RTO is expected to deliver the same advantages the organization has demonstrated across its central U.S. footprint for decades, including enhanced reliability, lower wholesale energy costs through regional dispatch, transparent and independent grid governance, and efficient planning that supports economic growth.

Operating as a coordinated system will strengthen real‑time situational awareness across a wider geography and enable the region to maximize diverse generating resources, navigate weather events and other threats to grid integrity, and optimize the use and planning of the region’s transmission network. These benefits will continue to grow as new members integrate into SPP’s planning processes, markets, and reliability toolset.

Learn more about the value of SPP’s regional approach to reliability coordination, market administration, and planning at www.SPP.org/value. SPP is also developing a separate wholesale market called Markets+ that will enable western utilities who are not RTO members to reap the benefits of a day-ahead market and other services. Learn more about Markets+ at www.MarketsPlus.org.

About SPP: SPP is a regional transmission organization: a not-for-profit corporation mandated by the Federal Energy Regulatory Commission to ensure reliable supplies of power, adequate transmission infrastructure and competitive wholesale electricity prices on behalf of its members in 17 states. SPP ensures electric reliability across a region spanning parts of the central and western U.S., provides energy services on a contract basis to customers in both the Eastern and Western Interconnections, and is developing a day-ahead energy market in the west: Markets+. The company’s headquarters are in Little Rock, Arkansas. Learn more at SPP.org.

Media Contacts
Seth Blomeley (sblomeley@spp.org)
Derek Wingfield (dwingfield@spp.org)

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SPP Service Territory Map and Expansion Participants

A map of SPP's expanded RTO service territory as of April 1, 2026. SPP now serves a 732,000 square-mile region comprising all or part of 17 states and that is home to 20 million people.

Entities joining or expanding their participation in the SPP RTO on April 1 include the following.

* = Entity that initiated the RTO expansion effort in the West
^ = Prior member of SPP expanding their participation as of April 1

• Basin Electric Power Cooperative* ^
• Central Montana Electric Power
• City of Aztec, New Mexico
• City of Farmington, New Mexico
• City of Fountain, Colorado
• City of Page, Arizona
• City of Sidney, Nebraska
• Colorado Springs Utilities*
• Delta-Montrose Electric Association
• Deseret Power Electric Cooperative*
• Guzman Energy ^
• Kimball Wind
• La Plata Electric Association
• Los Alamos County
• Municipal Energy Agency of Nebraska* ^
• Northwestern Energy ^
• Platte River Power Authority*
• Tenaska Power Services Co. ^
• The Energy Authority
• Tri-State Generation and Transmission Association* ^
• United Power ^
• Western Area Power Administration (WAPA) - Upper Great Plains region* ^
• WAPA - Colorado River Storage Project region*
• WAPA - Rocky Mountain region*
• Warren Air Force Base

STATEMENTS FROM ORGANIZATIONS JOINING OR EXPANDING PARTICIPATION IN THE SPP RTO

Travas Deal
CEO, Colorado Springs Utilities

“Joining SPP’s expanded RTO allows us to coordinate across a larger geographic footprint, strengthen reliability and provide our customers the most cost-effective power. We can take full advantage of an increasingly diverse energy mix, providing long term value for customers while supporting future economic growth across the region.”

Jason Frisbie
General Manager and CEO, Platte River Power Authority

“Actively participating in a fully organized energy market is the first and most significant element of our Resource Diversification Policy. We recognized early on that we could not achieve the noncarbon energy future our owner communities are asking for on our own. Joining the SPP RTO provides access to a much broader footprint of renewable resources while helping us maintain the reliability and affordability that our communities and their customers expect.”

Mark A. Gabriel
President and Chief Executive Officer, United Power

“Joining the Southwest Power Pool is an important step as our cooperative continues to work toward its vision of the new energy future. Being a market participant will provide the cooperative greater flexibility, access to more renewable resources, and the ability to maximize the co-op’s investments in the power grid – all of which will benefit our members today and into the future. Further, we look forward to all Coloradans benefitting from the depth and responsiveness of the SPP market.”

Chris Hansen, PhD
CEO, La Plata Electric Association

“Bringing an RTO to Colorado has been more than ten years in the making for me, and it’s incredibly meaningful to see it become a reality—especially now as CEO of a co-op that will directly benefit. For decades, the West has operated as 37 separate grid areas, driving higher costs, lower reliability, and increased emissions. A more integrated grid changes that. It improves all three and is one of the most impactful steps we can take to reduce pollution and show real leadership. LPEA joining SPP is a major milestone for our co-op and a meaningful step forward for the communities we serve.”

Duane Highley
CEO, Tri-State Generation and Transmission Cooperative

“Tri-State Generation and Transmission Association is delighted to join SPP’s RTO in the West. This step strengthens the value we deliver, enhances reliability, and supports long-term cost savings for our members and the communities they serve.”

Jack Johnston
CEO, Delta-Montrose Electric Association

“This is about preparing DMEA for the future. The electric grid is becoming more complex, and cooperatives that are connected to larger, coordinated systems are better positioned to adapt. Joining the Southwest Power Pool allows us to be part of that broader system—increasing flexibility, helping us access the most cost-efficient resources, and improving reliability with regional transmission planning and coordination. It’s a thoughtful step that reflects our long-term commitment to the members and communities we serve.”

Tom Mathine
Electrical Superintendent, City of Sidney, Nebraska

“Joining Southwest Power Pool marks an important step for the City of Sidney as we continue working to provide reliable and cost-effective power to our customers. We look forward to the opportunities this regional partnership brings.”

Joanie Teofilo
President and CEO, The Energy Authority

“The Energy Authority values its longstanding partnership with SPP and appreciates their collaborative approach. TEA is honored to support our clients as they navigate the evolving markets and remain committed to working alongside SPP to ensure a smooth and effective transition.”