#1TRI-STATE ロヤ RESILIENCE Whatever the future holds, WE'LL POWER IT. 2023 TRI-STATE INVESTOR PRESENTATION | 1#2RESILIENCE 2023 INVESTOR PRESENTATION Tri-State Generation and Transmission Association, Inc. 2023 TRI-STATE INVESTOR PRESENTATION | 2#3RESILIENCE Forward-looking statements detail our plans, objectives, goals, strategies, future events, future revenue or performance, capital expenditures, financing needs, or intentions relating to acquisitions, closure of facilities, business trends and other information that is not historical information. When used in this presentation, the words "estimates," "expects," "anticipates," "projects,” “plans,” “intends," "believes" and "forecasts" or future or conditional verbs, such as "will," "should," "could" or "may," and variations of such words or similar expressions, are intended to identify forward-looking statements. These forward-looking statements are subject to a number of risks, uncertainties and assumptions, including those described from time to time in our filings with the Securities and Exchange Commission. All forward-looking statements, including, without limitation, management's examination of historical operating trends and data, are based upon our current expectations and various assumptions. Our expectations and beliefs are expressed in good faith, and we believe there is a reasonable basis for them. However, we cannot provide certainty that management's expectations and beliefs will be achieved. There are a number of risks, uncertainties and other important factors that could cause our actual results to differ materially from the forward-looking statements contained in this presentation. 2023 TRI-STATE INVESTOR PRESENTATION | 3#4RESILIENCE POWER TODAY, POTENTIAL TOMORROW We are Tri-State, a not-for-profit wholesale power supplier with 45 members, including 42 electric cooperatives and public power districts across the Western United States. Together, we provide power to more than one million energy consumers in Colorado, Nebraska, New Mexico and Wyoming. ■ We believe that reliable power is the lifeblood of the rural West and is critical to the future of our communities. That's why we've made it our mission to supply reliable, affordable, responsibly-generated power to the farms, ranches, resorts and small towns that our members serve. Tri-State became FERC jurisdictional in September 2019. FERC provides a forum for all members, regardless of state or size, to have a voice and be considered by the regulator in rate matters. OUR MEMBERS' SERVICE TERRITORY ▪ 42 Utility Members Tri-State's member systems span areas in Colorado, Nebraska, New Mexico and Wyoming. 200,000 Square Miles With our members, we serve over a million consumers across an area greater than California. Our members are the sole state-certified providers of electric service to retail customers within their designated service territories. 2023 TRI-STATE INVESTOR PRESENTATION | 4#52030 RESILIENCY TARGETS RESILIENCE TODAY RELIABLE → MAJORITY FOSSIL → COST BASED → CONSTRAINED TRANSMISSION → LIMITED MARKET → 2030 RELIABLE AND RESILIENT MAJORITY RENEWABLE (WITH DISPATCHABLE BASELOAD) COMPETITIVE, FORMULAIC RATE EXPANDED TRANSMISSION FULL DAY-AHEAD MARKET 2023 TRI-STATE INVESTOR PRESENTATION | 5#6RESILIENCE STRATEGY MAP Member Needs Reliability & Resiliency Mission Affordability Flexibility Responsibility To provide our member systems a reliable, affordable and responsible supply of electricity in accordance with cooperative principles. Values Strategic Goals Operational Organizational Safety Integrity Teamwork Service Reliable & Resilient System Maintain members' top priority of a reliable and resilient system while implementing our transition. Business Competitiveness Provide the best long-term options for our members through competitive pricing, rates and cost management. Cooperative Innovation Create new growth opportunities by expanding the cooperative energy ecosystem to optimize coordination between member systems and their consumers. Employer of Choice Be a safe workplace and employer of choice by attracting and retaining an engaged, diverse and inclusive workforce that aligns with and supports the organization's success. Member Satisfaction Engage our members to collaboratively develop trust and deliver the greatest value. Regulatory Management Anticipate and manage regulatory, legislative, legal, and political impacts by engaging employees, members and external stakeholders. 2023 TRI-STATE INVESTOR PRESENTATION | 6#7RESPONSIBLE ENERGY PLAN In January 2020, we announced our Responsible Energy Plan to pursue a clean energy transition. The plan is designed to help us expand renewable generation and reduce greenhouse gas emissions while ensuring reliable, affordable and responsible electricity for our member cooperatives and public power districts, and for the communities they serve. Goals for our energy transition include: Eliminating all emissions from our coal-fired generating facilities in Colorado and New Mexico by 2030 In 2025, 50 percent of the electricity our Utility Members use is expected to come from clean energy sources More local renewables for Utility Members through contract flexibility Promoting participation in a regional transmission organization Expanding electric vehicle infrastructure, electrification, efficiency, and other energy services RESILIENCE 2023 TRI-STATE INVESTOR PRESENTATION | 7#8RESILIENCE RESPONSIBLE ENERGY PLAN We eliminated CO2 emissions from Tri-State-owned Escalante Generating Station in New Mexico in 2020. In Colorado, by 2030, we are targeting a 100% reduction in CO2 emissions from Tri-State-owned coal generation, a 90% reduction in CO2 emissions across generation we own or operate, and an 80% reduction in CO2 emissions associated with state wholesale electricity sales. At the same time, we will have brought more than 1,000 MW of new wind and solar resources online between 2021 and 2025, with plans to add additional resources through 2030 pending modeling of resource acquisition needs and approvals from the Colorado PUC. Our current goal is to supply our members with 70% clean energy system-wide by 2030. Closures include: Rifle Station in 2022 Craig Unit 1 in 2025 Craig Unit 2 in 2028 Craig Unit 3 by 2030 We're providing retraining and transition support for employees affected by these changes. We are also working with impacted communities, as well as state and federal government entities to find meaningful economic development opportunities to support a just transition. The Colorado PUC approved Tri-State's Phase I 2020 Electric Resource Plan and settlement agreement. Under the settlement, Tri-State agreed to reduce greenhouse gas emissions related to its wholesale electricity sales in Colorado (relative to 2005 baseline) as follows: 26% in 2025, 36% in 2026, 46% in 2027, and 80% in 2030. Tri-State's Phase II 2020 Electric Resource Plan preferred bid portfolio, with a new wind project coming online in 2026 is awaiting Colorado PUC approval, expected in May 2023. 2023 TRI-STATE INVESTOR PRESENTATION | 8#9RESILIENCE RESPONSIBLE ENERGY PLAN - 2022 PROGRESS HIGHLIGHTS Increase clean energy Over a third of energy our members used came from clean sources, and we set a renewable penetration record of 66% Reduce emissions Established our glidepath to reduce emissions associated with wholesale electricity sales in Colorado relative to a 2005 baseline by 26% in 2025, 36% in 2026, 46% in 2027, and 80% by 2030 Increase member flexibility Allocated 97 MW of 'open season' self-supply capacity to three additional members interested in taking a more active role in providing power in their communities, with a total allocation of 300 MW to six members Extend clean grid benefits Launched an energy innovations team to develop pathways for consumers to reduce their energy burden and emissions, with a focus on efficient electrification that reduces barriers to energy transition participation Support our communities In partnership with state and local leaders, Tri-State is in the process of hiring a facilitator to guide discussions to explore community assistance opportunities for the City of Craig and Moffatt County, in preparation for the retirement of Craig Station by 2030 Create a brighter future Collaborated with federal and state government, cooperative, eNGO and other stakeholders to develop cooperative clean energy provisions in the Inflation Reduction Act, resulting in over $15B in funding options and direct pay tax credits 2023 TRI-STATE INVESTOR PRESENTATION | 9#10OUR MEMBERS COLORADO EM Empire Electric Association, Inc., Cortez GC Gunnison County Electric Association, Inc., Gunnison. HL Highline Electric Association, Holyoke KC K.C. Electric Association, Inc., Hugo LP La Plata Electric Association, Inc., Durango MC Morgan County Rural Electric Association, Fort Morgan MP Mountain Parks Electric, Inc., Granby MV Mountain View Electric Association, Inc., Limon PV Poudre Valley Rural Electric Association, Inc., Fort Collins SI San Isabel Electric Association, Inc., Pueblo West UN United Power, Inc., Brighton WR White River Electric Association, Inc., Meeker YW Y-W Electric Association, Inc., Akron OUR RESOURCES 1. Headquarters and Operations Center Westminster, CO 2. Craig Station Craig, CO 3. Burlington Station Burlington, CO Fort Lupton, CO 4. J.M. Shafer Generating Station SV San Luis Valley Rural Electric Cooperative, Inc., Monte Vista SM San Miguel Power Association, Inc., Nucla SC Sangre de Cristo Electric Association, Inc., Buena Vista 5. SE Southeast Colorado Power Association, La Junta Limon Generating Station Limon, CO 6. Frank R. Knutson Generating Station Brighton, CO 7. Rifle Generating Station (retired in 2022) Rifle, CO PH Panhandle Rural Electric Membership Association, Alliance 8. Laramie River Station Wheatland, WY 9. Pyramid Generating Station NEBRASKA CR Chimney Rock Public Power District, Bayard MW Midwest Electric Cooperative Corporation, Grant NW Northwest Rural Public Power District, Hay Springs RS Roosevelt Public Power District, Scottsbluff WB Wheat Belt Public Power District, Sidney NEW MEXICO CN Central New Mexico Electric Cooperative, Inc., Mountainair CO Columbus Electric Cooperative, Inc., Deming CD Continental Divide Electric Cooperative, Inc., Grants JM Jemez Mountains Electric Cooperative, Inc., Española MO Mora-San Miguel Electric Cooperative, Inc., Mora NR Northern Rio Arriba Electric Cooperative, Inc., Chama OC Otero County Electric Cooperative, Inc., Cloudcroft SR Sierra Electric Cooperative, Inc., Elephant Butte SO Socorro Electric Cooperative, Inc., Socorro SW Southwestern Electric Cooperative, Inc., Clayton SP Springer Electric Cooperative, Inc., Springer WYOMING BH Big Horn Rural Electric Company, Basin CB Carbon Power & Light, Inc., Saratoga GL Garland Light & Power Company, Powell HP High Plains Power, Inc., Riverton HW High West Energy, Inc., Pine Bluffs NB Niobrara Electric Association, Inc., Lusk WL Wheatland Rural Electric Association, Wheatland WY Wyrulec Company, Torrington NON-UTILITY MEMBERS Ellgen Ranch Company MIECO, Inc. Olson's Greenhouses of Colorado, LLC Lordsburg, NM 10. David A. Hamil DC Tie Stegall, NE 11. Springerville Generating Station Springerville, AZ 12. Colowyo Mine Meeker, CO 13. New Horizon Mine (in full reclamation) Nucla, CO 14. Cimarron Solar - Colfax County, NM *Generation projects will be operational by the end of 2024 15. Kit Carson Windpower Kit Carson County, CO 16. Colorado Highlands Wind Logan County, CO 17. Carousel Wind Kit Carson County, CO 18. San Isabel Solar Las Animas County, CO 19. Alta Luna Solar Luna County, NM 20. Twin Buttes II Wind Prowers County, CO 21. Crossing Trails Wind Kit Carson & Cheyenne Counties, CO 22. Niyol Wind - Logan County, CO 23. Spanish Peaks Solar (2024) Las Animas County, CO 24. Spanish Peaks II Solar (2024) Las Animas County, CO 25. Coyote Gulch Solar (2025) Montezuma County, CO 26. Dolores Canyon Solar (2024) Dolores County, CO 27. Axial Basin Solar (2024) Moffat County, CO 28. Escalante Solar (2024) McKinley County, NM Tri-State also receives power from several small hydropower projects and under long-term contracts with the Western Area Power Administration and Basin Electric Power Cooperative. NEW MEXICO COLORADO CD 11 So SR GL BH LP GC CB MP SV NR CN WYOMING MO PV NB WL WY HW NEBRASKA NW PH CR WB MC HL 2216 MW MV SP SW SE YW KC 15 3 2023 TRI-STATE INVESTOR PRESENTATION | 10#11A DIVERSE & RELIABLE GENERATION PORTFOLIO How we generate and purchase power is important to our members. Tri-State is able to meet our members' needs by deploying clean energy resources via our long-term purchase power contracts, an efficient fleet of owned generation resources and market purchases. Our diverse generation portfolio leverages the West's plentiful natural resources to generate reliable and affordable electricity for our membership. We manage risks and costs of power generation by utilizing clean energy resources, including hydropower, wind and solar. We back that up with our efficient base load-serving coal generating units, intermediate load-serving natural gas combined- cycle generating units, and peak load-serving natural gas and oil combustion turbines. To manage the costs of energy production, we use coal from Tri-State-owned mines and contract for other coal supplies through our cooperative network. In addition, several of our gas plants are dual fuel and allow for alternative fuel options, protecting us from market price volatility. Coal-fired base load facilities Gas/oil-fired facilities Renewables-contracts including WAPA Other contracts, including Basin Coal-fired base load facilities Gas/oil-fired facilities Renewables-contracts including WAPA 2022 Generation Portfolio Capacity (as of Dec. 31, 2022) 35% 18% 33%* 14% MW 0 500 1000 1500 2000 Projected Generation Portfolio Capacity for 2030 14% 17% 57% Storage 2% Other contracts, including Basin 10% MW 0 1000 2000 3000 4000 RESILIENCE 2023 TRI-STATE INVESTOR PRESENTATION | 11#12OUR TRANSMISSION LINES SPAN THE WEST Reliable electricity hinges on our multi-state transmission network. It carries electricity from our generation resources to our members' distribution systems or to energy markets for sale. Our transmission network includes lines, substations, telecommunications, maintenance centers and field offices. Keeping the lights on for our members' consumers means our transmission system must be maintained and invested in regularly. Because we own most of our transmission network, we can more quickly add facilities and delivery points to serve our members' growing energy loads. Tri-State eastern interconnection member load has been in the SPP RTO since 2014, with Tri-State signing the SPP Membership Agreement in 2015. Regarding Tri-State's system in the western interconnection, Tri-State joined SPP's Western Energy Imbalance Service (WEIS) Market on February 1, 2021. In addition, Tri-State also expanded its participation in the CAISO Western Energy Imbalance Market (WEIM) real-time energy market into New Mexico on April 1, 2021. With other balancing authorities joining the WEIS in early spring 2023, all of Tri-State's remaining load and generation entered organized markets. 100% of Tri-State's generation and member load is currently in organized markets. RESILIENCE 422 BULK SUBSTATIONS 5,849 MILES OF LINE 2023 TRI-STATE INVESTOR PRESENTATION | 12#13RESILIENCE WE CONTINUE TO IMPROVE OUR TRANSMISSION NETWORK . • The Colorado Public Utility Commission has approved our request to add three new transmission lines in eastern Colorado Allows Tri-State to add capacity and expand to areas highly suitable for renewable generation projects The improvements will strengthen the system, allowing over 700 MW of new renewable generation to be incorporated into our system These upgrades and improvements will be focused on high capacity 230 kV lines The total project capex is expected to be more than $175 million over the next 5+ years WYOMING NEW MEXICO COLORADO LRS STORY BADGER CREEK THERMAL UPRATE new BIG SANDY- BADGER CREEK 230kV NEBRASKA BIG SANDY BURLINGTON BOONE LAMAR COMANCHE HUCKLEBERRY WALSENBURG new BOONE- HUCKLEBERRY 230kV GLADSTONE BURLINGTON- LAMAR 230kV 2023 TRI-STATE INVESTOR PRESENTATION | 13#14LONG-TERM WHOLESALE POWER CONTRACTS CREATE A STABLE AND PREDICTABLE REVENUE STREAM RESILIENCE Wholesale power contracts • 42 member contracts extend to 2050 Contract obligations • Contracts obligate Tri-State members to pay all of Tri-State's costs and expenses, including debt service, associated with owning and operating its power supply business Contract flexibility • Each member system has the option to provide up to 5% of its energy requirements from generation it owns or controls In addition, Tri-State has allocated 300 MW for members to self-supply up to 50% of their load. This allocation was granted to six members who participated in the application process 2023 TRI-STATE INVESTOR PRESENTATION | 14#15RESILIENCE 2022 TRI-STATE NUMBERS Tri-State's financial position provides the association with the continued ability to meet the future needs of the member distribution systems and their member-owners. Energy sales 18.6M MWh Total Energy Sold $1.5B OPERATING REVENUE 16.5M MWh MEMBER ENERGY SALES 2.1M MWh NON-MEMBER ENERGY SALES Pursuant to our master indenture, we are required to meet two main financial covenants: a Debt Service Ratio (DSR) of 1.10 and an Equity to Capitalization Ratio (ECR) of at least 18%. INDENTURE DSR FOR 2022 WAS 1.16 INDENTURE ECR FOR 2022 WAS 25.54% 3400 2700 2000 2020 2021 2022 *Total long-term debt continues to decline year-over-year $62.6M SAVED BY MEMBERS THROUGH WHOLESALE RATE REDUCTIONS $4.9B TOTAL ASSETS Energy Sold to Members Member Coincident Peak Demand 15.9 MWh 2,880 MW 2020 2020 15.7 MWh 2,974 MW 2021 2021 16.5 MWh 3,071 MW 2022 2022 2023 TRI-STATE INVESTOR PRESENTATION | 15#16RESILIENCE TOTAL CAPITALIZATION (as of 12/31/2022) Tri-State obtains capital through a variety of sources, including both public and private debt markets and margins. Additionally, we maintain equity at a level that provides for a healthy overall capital mix. We also manage interest rate risk by maintaining an appropriate balance between fixed rate and variable rate debt. Our overall liquidity is comprised of our $520M revolving credit facility, which supports a $500M commercial paper program, and cash on hand which equated to $102M as of December 31, 2022. SEC Total debt and equity Other 1% Commercial Paper 6% Term Loans 16% Registered Bonds 75% 25% Equity Debt Total Debt 12% 20% Private Placement 20% 144A Bonds Fixed vs. Variable rate debt 22.2% 77.8% Fixed Rate 84.7% Fixed Rate Variable Rate 2023 TRI-STATE INVESTOR PRESENTATION | 16#17RESILIENCE LOOK FORWARD Tri-State anticipates financing through a variety of sources, giving us flexibility around how we structure our debt portfolio in relation to interest rate risk, maturity profile and amortization structure. With our commitment to the cooperative business model and to serving our member systems, Tri-State stands apart from other utilities. Our liquidity, healthy sales growth and readiness to meet future obligations and challenges highlight our strong financial position. ■ Private placement SEC registered bonds ■ CoBank ■ CFC ■ Credit facility Commercial paper 2023 TRI-STATE INVESTOR PRESENTATION | 17#18TRANSITIONING TO FERC AND OUR EVOLVING MEMBERSHIP RESILIENCE Transition to FERC Single rate regulator benefits members as Tri-State increases member flexibility, renewables FERC rate regulation aligns Tri-State with rate regulation of other wholesale power providers Tri-State became fully rate regulated by FERC in 2019 Tri-State works constructively with state leaders to comply with resource planning, renewable energy and environmental compliance Formulary rate is scheduled to be filed with FERC in the summer of 2023 and we expect the formula rate to become effective on January 1, 2024 For more information regarding the dynamic process of our FERC transition please contact our investor relations team. [email protected] 2023 TRI-STATE INVESTOR PRESENTATION | 18#19RESILIENCE OUR DIFFERENT IS BETTER We are a member-owned cooperative This means we are not driven by profits; we're driven by the communities we serve. Unlike investor-owned utilities (IOUS), we have: No EPS targets • No high dividend payout ratios No EPS-driven M&A activity Our equity levels Our equity is comprised solely of patronage capital, similar to retained earnings of a for- profit company. We don't have paid-in capital on common stock. A valuable service Cooperatives took up the work of bringing electricity to rural communities when other power providers would not, working together to share the costs and risks of generating and transmitting electricity to deliver the benefits of this critical service. Even today, cooperatives serve far fewer consumers per mile than other types of utilities, but the value of membership is greater than ever. Long-term wholesale power contracts Contracts obligate our member systems to pay all of our costs and expenses, including debt service, associated with owning and operating our power supply business. Over the last few years, we have worked with our members to create more flexibility in our contracts to better serve the growing diversity of members. We are among the largest generation and transmission cooperatives in the country in terms of total assets, annual operating revenue, miles of transmission line owned, energy generation and sales. As a cooperative, everything we do is member- driven and member-focused. Our board of directors is made up of representatives from each of our 42 member systems, and with their guidance and governance, we continue to work with our member systems to serve the needs of communities and consumers across the West. 2023 TRI-STATE INVESTOR PRESENTATION | 19#20RESILIENCE TRI-STATE CREDIT STRENGTHS • • A large and growing portfolio of renewable energy backed by diverse dispatchable baseload, long term contracts for federal hydro power, and an intermediate and peak load fleet to provide affordable, reliable and responsible power Extensive transmission network, which enables Tri-State to improve reliability and add resources in the future Long-term wholesale power contracts for at least 95% of each member system's energy requirements to 2050 with 42 of our members . • • Safety record remains better than the national average Tri-State is located in a diverse region with significant wind and solar resources available Operating expenses have remained flat over the past five years Cost cutting initiatives are being pursued to sustain rate reductions For investor inquiries, please contact us at [email protected] 2023 TRI-STATE INVESTOR PRESENTATION | 20#21TRI-STATE WHATEVER THE FUTURE HOLDS WE'LL POWER IT.