Biggest changeSystem Peak Demand for the Electric Utilities’ retail customers for each of the last three years are listed below: System Peak Demand (in MWs) 2024 2023 2022 Summer Winter Summer Winter Summer Winter Colorado Electric 394 311 411 297 410 334 South Dakota Electric 388 346 378 289 403 355 Wyoming Electric (a) 309 314 312 301 294 281 ____________________ (a) See Recent Developments section of Management’s Discussion and Analysis of Financial Condition and Results of Operations in Item 7 in this Annual Report on Form 10-K for discussion on recent Wyoming Electric peaks. 12 Table of Contents As of December 31, 2024, our Electric Utilities’ ownership interests in electric generating plants were as follows: Unit Fuel Type Location Ownership Interest % (c) Owned Nameplate Capacity (MWs) In Service Date Colorado Electric: Busch Ranch I Wind Pueblo, Colorado 50% 14.5 2012 Peak View (a) (b) Wind Pueblo, Colorado 100% 60.8 2016 Pueblo Airport Generation #1-2 Natural Gas Pueblo, Colorado 100% 200.0 2011 Pueblo Airport Generation CT #6 Natural Gas Pueblo, Colorado 100% 40.0 2016 AIP Diesel Diesel Oil Pueblo, Colorado 100% 10.0 2001 Diesel #1 and #3-5 Diesel Oil Pueblo, Colorado 100% 8.0 1964 Diesel #1-5 Diesel Oil Rocky Ford, Colorado 100% 10.0 1964 South Dakota Electric: Cheyenne Prairie Natural Gas Cheyenne, Wyoming 58% 58.0 2014 Corriedale (b) Wind Cheyenne, Wyoming 62% 32.5 2020 Wygen III Coal Gillette, Wyoming 52% 60.3 2010 Neil Simpson II Coal Gillette, Wyoming 100% 90.0 1995 Wyodak Plant Coal Gillette, Wyoming 20% 80.5 1978 Neil Simpson CT Natural Gas Gillette, Wyoming 100% 40.0 2000 Lange CT Natural Gas Rapid City, South Dakota 100% 40.0 2002 Ben French Diesel #1-5 Diesel Oil Rapid City, South Dakota 100% 10.0 1965 Ben French CTs #1-4 Natural Gas/Diesel Oil Rapid City, South Dakota 100% 100.0 1977-1979 Wyoming Electric: Cheyenne Prairie Natural Gas Cheyenne, Wyoming 42% 42.0 2014 Cheyenne Prairie CT Natural Gas Cheyenne, Wyoming 100% 40.0 2014 Corriedale (b) Wind Cheyenne, Wyoming 38% 20.0 2020 Wygen II Coal Gillette, Wyoming 100% 95.0 2008 Integrated Generation: Wygen I Coal Gillette, Wyoming 76.5% 68.9 2003 Pueblo Airport Generation #4-5 Natural Gas Pueblo, Colorado 50.1% (d) 200.0 2012 Busch Ranch I Wind Pueblo, Colorado 50% 14.5 2012 Busch Ranch II (b) Wind Pueblo, Colorado 100% 59.4 2019 Total MW Capacity 1,394.4 ____________________ (a) The PTCs for Peak View flow back to customers through the RESA and ECA mechanisms as a reduction to Colorado Electric’s margins.
Biggest changeAs of December 31, 2025, our Electric Utilities’ ownership interests in electric generating plants were as follows: Unit Fuel Type Location Ownership Interest % (c) Owned Nameplate Capacity (MWs) In Service Date Colorado Electric: Busch Ranch I Wind Pueblo, Colorado 50% 14.5 2012 Peak View (a) (b) Wind Pueblo, Colorado 100% 60.8 2016 Pueblo Airport Generation #1-2 Natural Gas Pueblo, Colorado 100% 200.0 2011 Pueblo Airport Generation CT #6 Natural Gas Pueblo, Colorado 100% 40.0 2016 AIP Diesel Diesel Oil Pueblo, Colorado 100% 10.0 2001 Diesel #1-5 Diesel Oil Rocky Ford, Colorado 100% 10.0 1964 South Dakota Electric: Cheyenne Prairie Natural Gas Cheyenne, Wyoming 58% 58.0 2014 Corriedale (b) Wind Cheyenne, Wyoming 62% 32.5 2020 Wygen III Coal Gillette, Wyoming 52% 60.3 2010 Neil Simpson II Coal Gillette, Wyoming 100% 90.0 1995 Wyodak Plant Coal Gillette, Wyoming 20% 80.5 1978 Neil Simpson CT Natural Gas Gillette, Wyoming 100% 40.0 2000 Lange CT Natural Gas Rapid City, South Dakota 100% 40.0 2002 Ben French Diesel #1-5 Diesel Oil Rapid City, South Dakota 100% 10.0 1965 Ben French CTs #1-4 Natural Gas/Diesel Oil Rapid City, South Dakota 100% 100.0 1977-1979 Wyoming Electric: Cheyenne Prairie Natural Gas Cheyenne, Wyoming 42% 42.0 2014 Cheyenne Prairie CT Natural Gas Cheyenne, Wyoming 100% 40.0 2014 Corriedale (b) Wind Cheyenne, Wyoming 38% 20.0 2020 Wygen II Coal Gillette, Wyoming 100% 95.0 2008 Integrated Generation: Wygen I Coal Gillette, Wyoming 76.5% 68.9 2003 Pueblo Airport Generation #4-5 Natural Gas Pueblo, Colorado 50.1% (d) 200.0 2012 Busch Ranch I Wind Pueblo, Colorado 50% 14.5 2012 Busch Ranch II (b) Wind Pueblo, Colorado 100% 59.4 2019 Total MW Capacity 1,386.4 ____________________ (a) The PTCs for Peak View flow back to customers through the RESA and ECA mechanisms as a reduction to Colorado Electric’s margins.
The following table summarizes the mechanisms we have in place for each of our Gas Utilities: Gas Utility Jurisdiction Cost Recovery Mechanisms EECR/DSM Integrity Additions Bad Debt Weather Normal Gas Cost (a) Revenue Decoupling Arkansas Gas ☑ ☑ ☑ ☑ ☑ Colorado Gas (b) ☑ ☑ RMNG (c) Iowa Gas ☑ ☑ ☑ Kansas Gas ☑ ☑ ☑ ☑ Nebraska Gas ☑ ☑ ☑ Wyoming Gas ☑ ☑ ☑ ____________________ (a) All of our Gas Utilities, except where the Choice Gas Program is the only option, have GCAs that allow us to pass the prudently-incurred cost of gas and certain services through to the customer between rate reviews.
The following table summarizes the mechanisms we have in place for each of our Gas Utilities: Gas Utility Jurisdiction Cost Recovery Mechanisms EECR/DSM Integrity Additions Bad Debt Weather Normal Gas Cost (a) Revenue Decoupling Arkansas Gas ☑ ☑ ☑ ☑ ☑ Colorado Gas ☑ ☑ RMNG (b) Iowa Gas ☑ ☑ ☑ Kansas Gas ☑ ☑ ☑ ☑ Nebraska Gas ☑ ☑ ☑ ☑ Wyoming Gas ☑ ☑ ☑ ____________________ (a) All of our Gas Utilities, except where the Choice Gas Program is the only option, have GCAs that allow us to pass the prudently-incurred cost of gas and certain services through to the customer between rate reviews.
See a summary of key operating statistics in the Gas Utilities segment operating results within Management’s Discussion and Analysis of Financial Condition and Results of Operations in Item 7 of this Annual Report on Form 10-K. 16 Table of Contents Utility Regulation Characteristics Our Utilities are subject to regulation by a number of federal, state and other organizations, including, but not limited to, the following: • state public utility commissions, which have jurisdiction over services and facilities, rates and charges, accounting, valuation of property, depreciation rates, and various other matters; • the FERC, which oversees the acquisition and disposition of generation, transmission and other facilities, transmission of electricity and natural gas in interstate commerce, proposals to build and operate interstate natural gas pipelines and storage facilities, and wholesale purchases and sales of electric energy, among other things; • the NERC, which, through its regional entities, establishes and enforces mandatory reliability standards, subject to approval by the FERC, to ensure the reliability of the U.S. electric transmission and generation system, and to prevent major system blackouts; • the EPA, which has the responsibility to maintain and enforce national standards under a variety of environmental laws, in some cases delegating authority to state agencies.
See a summary of key operating statistics in the Gas Utilities segment operating results within Management’s Discussion and Analysis of Financial Condition and Results of Operations in Item 7 of this Annual Report on Form 10-K. 17 Table of Contents Utility Regulation Characteristics Our Utilities are subject to regulation by a number of federal, state and other organizations, including, but not limited to, the following: • state public utility commissions, which have jurisdiction over services and facilities, rates and charges, accounting, valuation of property, depreciation rates, and various other matters; • the FERC, which oversees the acquisition and disposition of generation, transmission and other facilities, transmission of electricity and natural gas in interstate commerce, proposals to build and operate interstate natural gas pipelines and storage facilities, and wholesale purchases and sales of electric energy, among other things; • the NERC, which, through its regional entities, establishes and enforces mandatory reliability standards, subject to approval by the FERC, to ensure the reliability of the U.S. electric transmission and generation system, and to prevent major system blackouts; • the EPA, which has the responsibility to maintain and enforce national standards under a variety of environmental laws, in some cases delegating authority to state agencies.
ITEM 1. BUSINESS History and Organization Black Hills Corporation, a South Dakota corporation (together with its subsidiaries, referred to herein as the “Company,” “we,” “us”, or “our”), is a customer-focused, growth-oriented utility company headquartered in Rapid City, South Dakota (incorporated in South Dakota in 1941).
ITEM 1. BUSINESS History and Organization Black Hills Corporation, a South Dakota corporation (together with its subsidiaries, referred to herein as the “Company,” "BHC," “we,” “us”, or “our”), is a customer-focused, growth-oriented utility company headquartered in Rapid City, South Dakota (incorporated in South Dakota in 1941).
Our Field Career Path Program (FCPP) promotes career growth for our frontline customer-facing employees through established standards of knowledge, skills, abilities, and performance. Employee Safety and Wellness Safety is one of our company values, a top priority in all we do and deeply embedded in our culture.
Our Field Career Path Program promotes career growth for our frontline customer-facing employees through established standards of knowledge, skills, abilities, and performance. Employee Safety and Wellness Safety is one of our company values, a top priority in all we do and deeply embedded in our culture.
(b) South Dakota Electric transmission line miles include 43 miles within the Common Use System. Material transmission services agreements are included in our disclosures in Note 3 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K. Seasonal Variations of Business. Our Electric Utilities are seasonal businesses and weather patterns may impact their operating results.
(b) South Dakota Electric transmission line miles include 131 miles within the Common Use System. Material transmission services agreements are included in our disclosures in Note 3 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K. Seasonal Variations of Business. Our Electric Utilities are seasonal businesses and weather patterns may impact their operating results.
Recent Tariff Filings See Note 2 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K for information regarding current regulatory activity. 19 Table of Contents FERC The Federal Power Act gives FERC exclusive rate-making jurisdiction over wholesale sales of electricity and the transmission of electricity in interstate commerce.
Recent Tariff Filings See Note 2 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K for information regarding current regulatory activity. 20 Table of Contents FERC The Federal Power Act gives FERC exclusive rate-making jurisdiction over wholesale sales of electricity and the transmission of electricity in interstate commerce.
We operate our business in the United States, reporting our operating results through our Electric Utilities and Gas Utilities segments. Certain unallocated corporate expenses that support our operating segments are presented as Corporate and Other. Our Electric Utilities segment generates, transmits and distributes electricity to approximately 225,000 electric utility customers in Colorado, Montana, South Dakota, and Wyoming.
We operate our business in the United States, reporting our operating results through our Electric Utilities and Gas Utilities segments. Certain unallocated corporate expenses that support our operating segments are presented as Corporate and Other. Our Electric Utilities segment generates, transmits and distributes electricity to approximately 227,000 electric utility customers in Colorado, Montana, South Dakota, and Wyoming.
(b) This facility qualifies for PTCs at $29/MWh under IRC 45 during the 10-year period beginning on the date the facility was originally placed in service. (c) Jointly owned facilities are discussed in Note 6 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K.
(b) This facility qualifies for PTCs at $30/MWh under IRC 45 during the 10-year period beginning on the date the facility was originally placed in service. (c) Jointly owned facilities are discussed in Note 6 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K.
Black Hills Energy Services provides natural gas supply to approximately 51,000 retail distribution customers under the Choice Gas Program in Nebraska and Wyoming. Additionally, we provide non-regulated services under the Service Guard Comfort Plan, Tech Services, and HomeServe.
Black Hills Energy Services provides natural gas supply to approximately 48,000 retail distribution customers under the Choice Gas Program in Nebraska and Wyoming. Additionally, we provide non-regulated services under the Service Guard Comfort Plan, Tech Services, and HomeServe.
(c) South Dakota Electric has WPSC authorization to accumulate certain energy efficiency costs in a regulatory asset with determination of recovery to be made in the next rate review. 18 Table of Contents Gas Utilities The following table provides regulatory information for each of our Gas Utilities: Subsidiary Jurisdiction Authorized Rate of Return on Equity Authorized Return on Rate Base Authorized Capital Structure Debt/Equity Authorized Rate Base (in millions) Effective Date Additional Regulatory Mechanisms Arkansas Gas (a) AR 9.85% 7.07% (b) 54%/46% $823.4 (c) 10/2024 GCA, Safety and Integrity Rider, EECR, Weather Normalization Adjustment, Billing Determinant Adjustment, Tax Adjustment Rider Colorado Gas (a) CO 9.30% 6.90% 49%/51% $378.4 5/2024 GCA, DSM, Gas Price Risk Management Rider, Energy Assistance Benefit Charge RMNG CO 9.50%-9.70% 6.93% 48%-50%/ 50%-52% $209.3 7/2023 Liquids/Off-system/Market Center Services Revenue Sharing Iowa Gas IA Black-box Settlement 7.21% Black-box Settlement $393.8 1/2025 GCA, EECR, System Safety and Maintenance Adjustment Rider, Gas Supply Optimization revenue sharing Kansas Gas KS Black-box Settlemen t Black-box Settlement Black-box Settlemen t Black-box Settlemen t 1/2022 GCA, Weather Normalization Tariff, Gas System Reliability Surcharge, Ad Valorem Tax Surcharge, Cost of Bad Debt Collected through GCA, Gas Supply Optimization revenue sharing Nebraska Gas (d) NE 9.50% 6.71% 50%/50% $504.2 (e) 3/2021 GCA, Cost of Bad Debt Collected through GCA, Choice Gas Program, SSIR, Bad Debt expense recovered through Choice Supplier Fee, Line Locates Surcharge, HEAT Program Wyoming Gas (a)(d) WY 9.85% 7.33% 49%/51% $450.8 2/2024 GCA, EECR, Rate Base Recovery on Acquisition Adjustment, Wyoming Integrity Rider, Choice Gas Program ____________________ (a) For additional information regarding recent rate review updates, see Note 2 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K.
(c) South Dakota Electric has WPSC authorization to accumulate certain energy efficiency costs in a regulatory asset with determination of recovery to be made in the next rate review. 19 Table of Contents Gas Utilities The following table provides regulatory information for each of our Gas Utilities: Subsidiary Jurisdiction Authorized Rate of Return on Equity Authorized Return on Rate Base Authorized Capital Structure Debt/Equity Authorized Rate Base (in millions) Effective Date Additional Regulatory Mechanisms Arkansas Gas (a) AR 9.85% 7.07% (b) 54%/46% $823.4 (c) 10/2024 GCA, Safety and Integrity Rider, EECR, Weather Normalization Adjustment, Billing Determinant Adjustment, Tax Adjustment Rider Colorado Gas CO 9.30% 6.90% 49%/51% $378.4 5/2024 GCA, DSM, Gas Price Risk Management Rider, Energy Assistance Benefit Charge RMNG CO 9.50%-9.70% 6.93% 48%-50%/ 50%-52% $209.3 7/2023 Liquids/Off-system/Market Center Services Revenue Sharing Iowa Gas (a) IA Black-box Settlement 7.21% Black-box Settlement $393.8 1/2025 GCA, EECR, System Safety and Maintenance Adjustment Rider, Gas Supply Optimization revenue sharing Kansas Gas (a) KS Black-box Settlemen t Black-box Settlement Black-box Settlemen t Black-box Settlemen t 8/2025 GCA, Weather Normalization Tariff, Gas System Reliability Surcharge, Ad Valorem Tax Surcharge, Cost of Bad Debt Collected through GCA, Gas Supply Optimization revenue sharing Nebraska Gas (a)(d) NE 9.85% 7.29% 49%/51% $781.3 (e) 1/2026 GCA, Cost of Bad Debt Collected through GCA, Choice Gas Program, SSIR, Bad Debt expense recovered through Choice Supplier Fee, HEAT Program, Weather Normalization Adjustment Wyoming Gas (d) WY 9.85% 7.33% 49%/51% $450.8 2/2024 GCA, EECR, Rate Base Recovery on Acquisition Adjustment, Wyoming Integrity Rider, Choice Gas Program ____________________ (a) For additional information regarding recent rate review updates, see Note 2 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K.
Demand for electricity is sensitive to seasonal cooling, heating and industrial load requirements, as well as market price. In particular, cooling demand is often greater in the summer and heating demand is often greater in the winter. 14 Table of Contents Competition. We generally have limited competition for the retail generation and distribution of electricity in our service areas.
Demand for electricity is sensitive to seasonal cooling, heating and industrial load requirements, as well as market price. In particular, cooling demand is often greater in the summer and heating demand is often greater in the winter. Competition. We generally have limited competition for the retail generation and distribution of electricity in our service areas.
We produced approximately 3.7 million tons of coal in 2024. The mine provides low-sulfur coal directly to these five power plants via a conveyor belt system, minimizing transportation costs. The fuel can be delivered to our adjacent power plants at very cost competitive prices (i.e., $1.19 per MMBtu for year ended December 31, 2024) when compared to alternatives.
We produced approximately 3.3 million tons of coal in 2025. The mine provides low-sulfur coal directly to these five power plants via a conveyor belt system, minimizing transportation costs. The fuel can be delivered to our adjacent power plants at very cost competitive prices (i.e., $1.26 per MMBtu for year ended December 31, 2025) when compared to alternatives.
Demand for natural gas can also be impacted by summer temperatures and precipitation, which can affect demand for irrigation. Competition. We generally have limited competition for the retail distribution of natural gas in our service areas. Various restructuring and competitive initiatives have been discussed in several of the states in which our utilities operate.
Demand for natural gas can also be impacted by summer temperatures and precipitation, which can affect demand from agricultural customers. Competition. We generally have limited competition for the retail distribution of natural gas in our service areas. Various restructuring and competitive initiatives have been discussed in several of the states in which our utilities operate.
Our development and retention efforts include internal and external skills training, career development programs, and competitive compensation. Our compensation programs are designed to be strategically aligned, externally competitive, internally equitable, personally motivating, cost effective, and legally compliant. We monitor employee engagement through regular engagement surveys to gather valuable insights and feedback.
Our development and retention efforts include skills training, development programs, and competitive compensation. Our compensation programs are designed to be strategically aligned, externally competitive, internally equitable, personally motivating, cost effective, and legally compliant. We monitor employee engagement through engagement surveys to gather valuable insights and feedback.
Our Team As of December 31, 2024 As of December 31, 2023 Total employees 2,841 2,874 Women in executive leadership positions (a) 32% 29% Gender diversity (women as a % of total employees) 24% 24% Represented by a union 25% 25% Military veterans 9% 10% Ethnic diversity (non-white employees as a % of total) 15% 15% For the year ended December 31, 2024 For the year ended December 31, 2023 Number of external hires 303 293 External hires gender diversity (as a % of total external hires) 29% 27% External hires ethnic diversity (as a % of total external hires) 25% 24% Turnover rate (b) 11% 12% Retirement rate 3% 3% ____________________ (a) Executive leadership positions are defined as positions with Vice President, Senior Vice President, or Chief in their title.
Our Team As of December 31, 2025 As of December 31, 2024 Total employees 2,795 2,841 Women in executive leadership positions (a) 30% 32% Gender diversity (women as a % of total employees) 24% 24% Represented by a union 25% 25% Military veterans 10% 9% Ethnic diversity (non-white employees as a % of total) 15% 15% For the year ended December 31, 2025 For the year ended December 31, 2024 Number of external hires 306 303 External hires gender diversity (as a % of total external hires) 25% 29% External hires ethnic diversity (as a % of total external hires) 20% 25% Turnover rate (b) 12% 11% Retirement rate 3% 3% ____________________ (a) Executive leadership positions are defined as positions with Vice President, Senior Vice President, or Chief in their title.
Our Electric Utilities own 1,394 MW of generation and 9,196 miles of electric transmission and distribution lines. Our Gas Utilities segment serves approximately 1,128,000 natural gas utility customers in Arkansas, Colorado, Iowa, Kansas, Nebraska, and Wyoming.
Our Electric Utilities own 1,386 MW of generation and 9,478 miles of electric transmission and distribution lines. Our Gas Utilities segment serves approximately 1,138,000 natural gas utility customers in Arkansas, Colorado, Iowa, Kansas, Nebraska, and Wyoming.
Our Electric Utilities generate, transmit, and distribute electricity to our retail customers. Our electric generating facilities and power purchase agreements provide for the supply of electricity principally to our retail customers. We also sell excess power to other utilities and marketing companies, including our affiliates.
Electric Utilities We conduct electric utility operations through our Colorado, South Dakota, and Wyoming subsidiaries. Our Electric Utilities generate, transmit, and distribute electricity to our retail customers. Our electric generating facilities and power purchase agreements provide for the supply of electricity principally to our retail customers. We also sell excess power to other utilities and marketing companies, including our affiliates.
For the year ended December 31, 2024 Days Away, Restricted, or Transferred (incidents per 200,000 hours worked) 1.0 Proactive Safety Activities per Employee 6 % of injuries reported within 1 day 91.5% 22 Table of Contents
For the year ended December 31, 2025 Days Away, Restricted, or Transferred (incidents per 200,000 hours worked) 0.6 Proactive Safety Activities per Employee 9 % of injuries reported within 1 day 96.3% 23 Table of Contents
Transmission investments are recovered from wholesale transmission customers under the FERC Formula Transmission rate. The rate base associated with FERC assets is not displayed separate from that collected through the state recovery mechanisms, to avoid double counting. Authorized totals for Colorado Electric and Wyoming Electric include amounts recovered through base rates and the authorized regulatory mechanisms.
(b) For both Wyoming Electric and Colorado Electric retail customers, transmission investments are recovered through retail rates rather than FERC Transmission Tariffs. Transmission investments are recovered from wholesale transmission customers under the FERC Formula Transmission rate. The rate base associated with FERC assets is not displayed separate from that collected through the state recovery mechanisms, to avoid double counting.
Every leader is responsible for creating and implementing an action plan based on their team’s engagement survey results, while the company develops broader action plans to address organization-wide opportunities. Our career development programs include management onboarding, leadership development programs, mentoring programs, stretch opportunities, and more. Internal training opportunities include corporate-wide and specialized training opportunities for different job functions.
Every leader creates and implements action plans based on their team’s engagement survey results, and the company develops broader action plans to address organization-wide opportunities. Our development programs include management onboarding, leadership development, mentoring, stretch opportunities, and more. Internal development opportunities include corporate-wide and specialized learning for different job functions.
Total Employees Number of Employees As of December 31, 2024 Electric Utilities 423 Gas Utilities 1,175 Corporate and Other 1,243 Total 2,841 At December 31, 2024, approximately 18% of our total employees and 20% of our Electric and Gas Utilities employees were eligible for retirement (age 55 with at least 5 years of service). 21 Table of Contents Collective Bargaining Agreements At December 31, 2024, certain employees of our Electric Utilities and Gas Utilities were covered by the collective bargaining agreements as shown in the table below.
Total Employees Number of Employees As of December 31, 2025 Electric Utilities 421 Gas Utilities 1,184 Corporate and Other 1,190 Total 2,795 At December 31, 2025, approximately 18% of our total employees and 19% of our Electric and Gas Utilities employees were eligible for retirement (age 55 with at least 5 years of service). 22 Table of Contents Collective Bargaining Agreements At December 31, 2025, certain employees of our Electric Utilities and Gas Utilities were covered by the collective bargaining agreements as shown in the table below.
We have undertaken initiatives to meet current requirements and to prepare for anticipated future regulations, reduce GHG emissions, and respond to state renewable and energy efficiency goals.
We have undertaken initiatives to meet current requirements and to prepare for anticipated future regulations, reduce GHG emissions, and respond to state renewable and energy efficiency goals. Compliance with future environmental regulations could result in substantial cost.
As of December 31, Retail Customers by Customer Class 2024 2023 2022 Residential 882,232 871,930 864,038 Commercial 85,594 84,917 85,203 Industrial 2,174 2,179 2,189 Transportation 158,355 157,367 155,685 Total Natural Gas Retail Customers at End of Year 1,128,355 1,116,393 1,107,115 As of December 31, Retail Customers by Business Unit 2024 2023 2022 Arkansas Gas 189,240 186,216 183,270 Colorado Gas 215,190 211,155 208,060 Iowa Gas 164,134 163,281 162,801 Kansas Gas 120,225 119,407 118,599 Nebraska Gas 304,429 302,167 301,007 Wyoming Gas 135,137 134,167 133,378 Total Natural Gas Retail Customers at End of Year 1,128,355 1,116,393 1,107,115 We procure natural gas for our distribution customers from a diverse mix of producers, processors, and marketers and generally use financial hedges, physical fixed-price purchases, and market-based price purchases to achieve dollar-cost averaging within our natural gas portfolio.
As of December 31, Retail Customers by Customer Class 2025 2024 2023 Residential 891,484 882,232 871,930 Commercial 86,299 85,594 84,917 Industrial 2,219 2,174 2,179 Transportation 158,150 158,355 157,367 Total Natural Gas Retail Customers at End of Year 1,138,152 1,128,355 1,116,393 16 Table of Contents As of December 31, Retail Customers by Business Unit 2025 2024 2023 Arkansas Gas 191,538 189,240 186,216 Colorado Gas 218,140 215,190 211,155 Iowa Gas 165,049 164,134 163,281 Kansas Gas 120,987 120,225 119,407 Nebraska Gas 306,452 304,429 302,167 Wyoming Gas 135,986 135,137 134,167 Total Natural Gas Retail Customers at End of Year 1,138,152 1,128,355 1,116,393 We procure natural gas for our distribution customers from a diverse mix of producers, processors, and marketers and generally use financial hedges, physical fixed-price purchases, and market-based price purchases to achieve dollar-cost averaging within our natural gas portfolio.
As of December 31, Retail Customers by Customer Class 2024 2023 2022 Residential 192,716 190,776 188,921 Commercial 31,210 30,491 30,404 Industrial 83 84 82 Municipal 1,079 989 1,024 Total Electric Retail Customers at End of Year 225,088 222,340 220,431 As of December 31, Retail Customers by Business Unit 2024 2023 2022 Colorado Electric 101,455 100,907 100,573 South Dakota Electric 77,941 76,479 75,169 Wyoming Electric 45,692 44,954 44,689 Total Electric Retail Customers at End of Year 225,088 222,340 220,431 Capacity and Demand.
As of December 31, Retail Customers by Customer Class 2025 2024 2023 Residential 194,735 192,716 190,776 Commercial 31,240 31,210 30,491 Industrial 86 83 84 Municipal 1,039 1,079 989 Total Electric Retail Customers at End of Year 227,100 225,088 222,340 As of December 31, Retail Customers by Business Unit 2025 2024 2023 Colorado Electric 102,152 101,455 100,907 South Dakota Electric 78,976 77,941 76,479 Wyoming Electric 45,972 45,692 44,954 Total Electric Retail Customers at End of Year 227,100 225,088 222,340 13 Table of Contents Capacity and Demand.
The renewable energy from these PPAs is used to serve our expanding partnerships with LPCS customers. 13 Table of Contents Our Electric Utilities’ weighted average cost of fuel utilized to generate electricity and the average price paid for purchased power (excluding contracted capacity) per MWh for the years ended December 31 were as follows: Fuel and Purchased Power (dollars per MWh) 2024 2023 2022 Coal $ 13.87 $ 13.40 $ 12.76 Natural Gas 15.64 20.20 37.09 Wind — — — Total Generated Weighted Average Fuel Cost 12.90 14.27 17.57 Coal, Natural Gas, Diesel Oil and Other Market Purchases 67.04 55.61 66.35 Wind and Solar Purchases 38.70 34.99 33.78 Total Purchased Power Weighted Average Cost 52.79 51.68 61.56 Total Weighted Average Fuel and Purchased Power Cost $ 24.66 $ 25.39 $ 32.82 Purchased Power.
Our Electric Utilities’ weighted average cost of fuel utilized to generate electricity and the average price paid for purchased power (excluding contracted capacity) per MWh for the years ended December 31 were as follows: Fuel and Purchased Power (dollars per MWh) 2025 2024 2023 Coal $ 16.59 $ 13.87 $ 13.40 Natural Gas 18.00 15.64 20.20 Wind — — — Total Generated Weighted Average Fuel Cost 15.28 12.90 14.27 Coal, Natural Gas, Diesel Oil and Other Market Purchases 51.13 67.04 55.61 Wind and Solar Purchases 38.74 38.70 34.99 Total Purchased Power Weighted Average Cost 46.24 52.79 51.68 Total Weighted Average Fuel and Purchased Power Cost $ 26.98 $ 24.66 $ 25.39 Purchased Power.
(b) The diesel oil-fueled generating units are generally used as supplemental peaking units. Power generated from these units, as a percentage of total power supply, was 0.0% for each of the years presented.
Power generated from these units, as a percentage of total power supply, was 0.0% for each of the years presented.
Utility Number of Employees Union Affiliation Expiration Date of Collective Bargaining Agreement Colorado Electric 109 IBEW Local 667 April 15, 2027 South Dakota Electric 118 IBEW Local 1250 March 31, 2027 South Dakota Electric 6 IBEW Local 1250 September 29, 2028 Wyoming Electric 28 IBEW Local 111 June 30, 2029 Total Electric Utilities 261 Iowa Gas 127 IBEW Local 204 January 31, 2026 Kansas Gas 15 Communications Workers of America, AFL-CIO Local 6407 December 31, 2029 Nebraska Gas 92 IBEW Local 244 March 13, 2025 Nebraska Gas 127 CWA Local 7476 October 30, 2026 Wyoming Gas 13 IBEW Local 111 June 30, 2029 Wyoming Gas 81 CWA Local 7476 October 30, 2026 Total Gas Utilities 455 Total 716 Development and Retention Developing and retaining talent is critical to our continued success.
Utility Number of Employees Union Affiliation Expiration Date of Collective Bargaining Agreement Colorado Electric 101 IBEW Local 667 April 15, 2027 South Dakota Electric 119 IBEW Local 1250 March 31, 2027 South Dakota Electric 7 IBEW Local 1250 September 29, 2028 Wyoming Electric 30 IBEW Local 111 June 30, 2029 Total Electric Utilities 257 Iowa Gas 124 IBEW Local 204 May 1, 2026 Kansas Gas 15 CWA Local 6423 December 31, 2029 Nebraska Gas 92 IBEW Local 244 March 12, 2030 Nebraska Gas 124 CWA Local 7476 October 30, 2026 Wyoming Gas 14 IBEW Local 111 June 30, 2029 Wyoming Gas 76 CWA Local 7476 October 30, 2026 Total Gas Utilities 445 Total 702 Development and Retention Developing, engaging, and retaining talent is critical to our continued success.
These tariffs allow the utility a return on the investment. 17 Table of Contents Electric Utilities The following table provides regulatory information for each of our Electric Utilities: Subsidiary Jurisdiction Authorized Rate of Return on Equity Authorized Return on Rate Base Authorized Capital Structure Debt/Equity Authorized Rate Base (in millions) Effective Date Additional Regulatory Mechanisms Percentage of Power Marketing Profit Shared with Customers Colorado Electric (c) CO 9.37% 7.43% 48%/52% $653.7 (a) 1/2017 ECA, TCA, PCCA, EECR/DSM, RESA, TEPR, Energy Assistance Benefit Charge, CEPR 90% CO 9.37% 6.02% 67%/33% $57.9 1/2017 CACJA Adjustment Rider N/A FERC 9.80% 6.45% 53%/47% (a) 9/2022 FERC Transmission Tariff N/A South Dakota Electric WY 9.90% 8.13% 47%/53% $46.8 10/2014 ECA 65% SD Black-box Settlement 7.76% Black-box Settlement $543.9 10/2014 ECA, TFA, EIA 70% FERC 10.80% 8.76% 43%/57% $200.4 (b) 2/2009 FERC Transmission Tariff N/A Wyoming Electric WY 9.75% 7.48% 48%/52% $551.2 (a) 3/2023 PCA, EECR/DSM, Rate Base Recovery on Acquisition Adjustment, TCAM N/A FERC 9.90% 8.77% 44%/56% (a) 1/2019 FERC Transmission Tariff N/A ____________________ (a) For both Wyoming Electric and Colorado Electric retail customers, transmission investments are recovered through retail rates rather than FERC Transmission Tariffs.
In addition, some jurisdictions allow us to recover certain costs or earn a return on capital investments placed in service between base rate reviews through approved rider tariffs, such as energy efficiency plan costs and system safety and integrity investments. 18 Table of Contents Electric Utilities The following table provides regulatory information for each of our Electric Utilities: Subsidiary Jurisdiction Authorized Rate of Return on Equity Authorized Return on Rate Base Authorized Capital Structure Debt/Equity Authorized Rate Base (in millions) Effective Date Additional Regulatory Mechanisms Percentage of Power Marketing Profit Shared with Customers Colorado Electric (a) CO 9.30%-9.50% 6.9% 51%-53%/ 47%-49% $663.8 (b) 3/2025 ECA, TCA, PCCA, EECR/DSM, RESA, TEPR, Energy Assistance Benefit Charge, CEPR 90% FERC 9.80% 6.45% 53%/47% (b) 9/2022 FERC Transmission Tariff N/A South Dakota Electric WY 9.90% 8.13% 47%/53% $46.8 10/2014 ECA, EECR/DSM 65% SD Black-box Settlement 7.76% Black-box Settlement $543.9 10/2014 ECA, TFA, EIA 70% FERC 10.80% 8.76% 43%/57% $207.3 (c) 2/2009 FERC Transmission Tariff N/A Wyoming Electric WY 9.75% 7.48% 48%/52% $551.2 (a) 3/2023 PCA, EECR/DSM, Rate Base Recovery on Acquisition Adjustment, TCAM N/A FERC 9.90% 8.77% 44%/56% (b) 1/2019 FERC Transmission Tariff N/A ____________________ (a) For additional information regarding recent rate review updates, see Note 2 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K.
In addition to company-owned regulated underground natural gas storage assets in Arkansas, Colorado, and Wyoming, we also contract with third-party transportation providers for natural gas storage service to provide gas supply during the winter heating season and to meet peak day customer demand for natural gas. 15 Table of Contents The following table summarizes certain information regarding our company-owned regulated underground gas storage facilities as of December 31, 2024: Working Capacity (Mcf) Cushion Gas (Mcf) Total Capacity (Mcf) Maximum Daily Withdrawal Capability (Mcfd) Arkansas Gas 8,442,700 13,149,040 21,591,740 196,000 Colorado Gas 2,361,495 6,164,715 8,526,210 30,000 Wyoming Gas 5,733,900 17,545,600 23,279,500 36,000 Total 16,538,095 36,859,355 53,397,450 262,000 The following table summarizes certain information regarding our system infrastructure as of December 31, 2024: Intrastate Gas Transmission Pipelines Gas Distribution Mains Gas Distribution Service Lines (in Line Miles) Arkansas Gas 875 5,317 1,411 Colorado Gas 682 7,290 2,245 Iowa Gas 173 2,938 3,729 Kansas Gas 339 3,096 1,510 Nebraska Gas 1,313 8,658 2,967 Wyoming Gas 1,266 3,618 1,745 Total 4,648 30,917 13,607 Seasonal Variations of Business.
The following table summarizes certain information regarding our company-owned regulated underground gas storage facilities as of December 31, 2025: Working Capacity (Mcf) Cushion Gas (Mcf) Total Capacity (Mcf) Maximum Daily Withdrawal Capability (Mcfd) Arkansas Gas 8,442,700 13,149,040 21,591,740 196,000 Colorado Gas 2,361,495 6,164,715 8,526,210 30,000 Wyoming Gas 5,733,900 17,545,600 23,279,500 36,000 Total 16,538,095 36,859,355 53,397,450 262,000 The following table summarizes certain information regarding our system infrastructure as of December 31, 2025: Intrastate Gas Transmission Pipelines Gas Distribution Mains Gas Distribution Service Lines (in Line Miles) Arkansas Gas 875 5,221 1,441 Colorado Gas 667 7,238 1,881 Iowa Gas 177 2,952 2,900 Kansas Gas 304 3,107 1,524 Nebraska Gas 1,313 8,712 3,091 Wyoming Gas 1,245 3,631 3,142 Total 4,581 30,861 13,979 Seasonal Variations of Business.
Nearly all of the mine’s production is sold to our on-site generation facilities under long-term supply contracts. As of December 31, 2024, we estimated our recoverable reserves to be approximately 175 million tons, based on a life-of-mine engineering study utilizing currently available drilling data and geological information prepared by internal engineering analyses.
As of December 31, 2025, we estimated our recoverable reserves to be approximately 172 million tons, based on a life-of-mine engineering study utilizing currently available drilling data and geological information prepared by internal engineering analyses. The recoverable reserve life is equal to approximately 51 years at the current production levels. Transmission and Distribution.
(b) Includes $183.3 million in 2024 rate base for the 2024 Projected Common Use System formula rate that is updated annually and $17.1 million in rate base for the Transmission Tie that is based on the approved stated rate from 2005.
Authorized totals for Colorado Electric and Wyoming Electric include amounts recovered through base rates and the authorized regulatory mechanisms. (c) Includes $190.2 million in 2025 rate base for the 2025 Projected Common Use System formula rate that is updated annually and $17.1 million in rate base for the Transmission Tie that is based on the approved stated rate from 2005.
If we fail to comply with applicable statutes and the PHMSA Office of Pipeline Safety’s rules and related regulations and orders, we could be subject to significant penalties and fines. Environmental Matters We have clean energy goals to reduce GHG emissions that are based on prudent and proven solutions while minimizing cost impacts to and ensuring safety of our customers.
If we fail to comply with applicable statutes and the PHMSA Office of Pipeline Safety’s rules and related regulations and orders, we could be subject to significant penalties and fines. Environmental Matters We are subject to significant state and federal environmental regulations that encourage the use of clean energy technologies and regulate emissions of GHGs.
We also jointly operate an electric transmission system, referred to as the Common Use System, with Basin Electric Power Cooperative and Powder River Energy Corporation. Each participant in the Common Use System individually owns assets that are operated together for a single system. The Common Use System also provides transmission service to our Transmission Tie.
Each participant in the Common Use System individually owns assets that are operated together for a single system. The Common Use System also provides transmission service to our Transmission Tie. South Dakota Electric owns 35% of the Transmission Tie.
Our Electric Utilities’ power supply by resource as a percent of the total power supply for our energy needs for the years ended December 31 was as follows: Power Supply 2024 2023 2022 Coal 32.5 % 35.0 % 35.1 % Natural Gas 29.4 % 26.4 % 18.8 % Wind (a) 8.6 % 8.9 % 11.4 % Total Generated (b) 70.5 % 70.3 % 65.3 % Coal, Natural Gas, Diesel Oil and Other Market Purchases 14.7 % 24.1 % 29.6 % Wind and Solar Purchases (c) 14.8 % 5.6 % 5.1 % Total Purchased 29.5 % 29.7 % 34.7 % Total 100.0 % 100.0 % 100.0 % ____________________ (a) Wind generation decreased due to the sale of Northern Iowa Windpower assets in March 2023.
(d) Non-controlling interest is discussed in Note 12 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K. 14 Table of Contents Our Electric Utilities’ power supply by resource as a percent of the total power supply for our energy needs for the years ended December 31 was as follows: Power Supply 2025 2024 2023 Coal 25.5 % 32.5 % 35.0 % Natural Gas 29.3 % 29.4 % 26.4 % Wind 7.4 % 8.6 % 8.9 % Total Generated (a) 62.2 % 70.5 % 70.3 % Coal, Natural Gas, Diesel Oil and Other Market Purchases 22.9 % 14.7 % 24.1 % Wind and Solar Purchases 14.9 % 14.8 % 5.6 % Total Purchased 37.8 % 29.5 % 29.7 % Total 100.0 % 100.0 % 100.0 % ____________________ (a) The diesel oil-fueled generating units are generally used as supplemental peaking units.
At December 31, 2024, our Electric Utilities owned the electric transmission and distribution lines shown below: Utility State Transmission (a) Distribution (in Line Miles) Colorado Electric Colorado 655 3,222 South Dakota Electric (b) South Dakota, Wyoming 1,234 2,627 Wyoming Electric Wyoming 88 1,370 1,977 7,219 ____________________ (a) Electric transmission line miles include voltages of 69 kV and above.
The Transmission Tie is further discussed in Note 6 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K. 15 Table of Contents At December 31, 2025, our Electric Utilities owned the electric transmission and distribution lines shown below: Utility State Transmission (a) Distribution (in Line Miles) Colorado Electric Colorado 655 3,229 South Dakota Electric (b) South Dakota, Wyoming 1,193 2,662 Wyoming Electric Wyoming 366 1,373 2,214 7,264 ____________________ (a) Electric transmission line miles include voltages of 69 kV and above.
Our Gas Utilities own and operate 4,648 miles of intrastate gas transmission pipelines and 44,524 miles of gas distribution mains and service lines, seven natural gas storage sites, more than 50,000 horsepower of compression, and 516 miles of gathering lines. Electric Utilities We conduct electric utility operations through our Colorado, South Dakota, and Wyoming subsidiaries.
Our Gas Utilities own and operate 4,581 miles of intrastate gas transmission pipelines and 44,840 miles of gas distribution mains and service lines, seven natural gas storage sites, more than 50,000 horsepower of compression, and 494 miles of gathering lines. Proposed Merger with NorthWestern BHC and NorthWestern entered into an all-stock business combination on August 18, 2025.
The recoverable reserve life is equal to approximately 47 years at the current production levels. Transmission and Distribution. Through our Electric Utilities, we own electric transmission and distribution systems composed of high voltage lines (greater than 69 kV) and low voltage lines (69 kV or less).
Through our Electric Utilities, we own electric transmission and distribution systems composed of high voltage lines (greater than 69 kV) and low voltage lines (69 kV or less). We also jointly operate an electric transmission system, referred to as the Common Use System, with Basin Electric Power Cooperative and Powder River Energy Corporation.
We continually assess risk and develop mitigation strategies to manage and ensure compliance across the enterprise successfully and responsibly. For additional information on environmental matters, see Item 1A and Note 3 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K.
For additional information on environmental matters, see Item 1A - Risk Factors and Note 3 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K. 21 Table of Contents Clean Energy Goals In November 2020, we announced clean energy goals to reduce GHG emissions intensity for our Electric Utilities by 40% by 2030 and 70% by 2040 and achieve GHG reductions of 50% by 2035 for our Gas Utilities.
(c) For additional information regarding recent rate review updates, see Note 2 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K.
The combined company will serve approximately 0.7 million electric utility customers and 1.5 million gas utility customers across eight states. See additional information in Item 1A - Risk Factors and Note 17 of the Notes to Consolidated Financial Statements in this Annual Report on Form 10-K.
We are currently evaluating the impact of these rules through our integrated resource plans and believe that costs incurred as a result of the new rules will be recoverable through our regulatory mechanisms. Environmental risk changes constantly with the implementation of new or modified regulations, changing stakeholder interests and needs, and through the introduction of innovative work practices and technologies.
We will evaluate the impacts of the final rule at that time. Environmental risk changes frequently with the implementation of new or modified regulations, changing stakeholder interests and needs, and through the introduction of innovative work practices and technologies. We continually assess risk and develop mitigation strategies to manage and ensure compliance across the enterprise successfully and responsibly.