#1wwwwwww RIVE RIVE KNIFE RIVER Investor Day COMPETITIVE EDGE May 18, 2023#2Forward Looking Statements Certain statements and information in this presentation may constitute forward-looking statements. These forward-looking statements include, without limitation, statements concerning plans, objectives, goals, projections, strategies, future events or performance, and underlying assumptions and other statements, which are not statements of historical facts. In some cases, you can identify forward-looking statements by terminology such as "may," "will," "intends," "should," "expect," "plan," "anticipate,” “believe,” “estimate," "propose,” “predict,” “potential" or "continue," the negative of such terms or other comparable terminology. These forward-looking statements are based on our current expectations and beliefs concerning future developments and their potential effect on us. While management believes that these forward-looking statements are reasonable as and when made, there can be no assurance that future developments affecting us will be those that we anticipate. All comments concerning our expectations for future revenues and operating results are based on our forecasts for our existing operations and do not include the potential impact of any future acquisitions. Our forward-looking statements involve significant risks and uncertainties (some of which are beyond our control) and assumptions that could cause actual results to differ materially from our historical experience and our present expectations or projections. Important factors that could cause actual results to differ materially from those in the forward-looking statements include, but are not limited to, risks associated with the impact, timing or terms of the spinoff; risks associated with the expected benefits and costs of the spinoff, including the risk that the expected benefits of the spinoff will not be realized within the expected time frame, in full or at all, and the risk that conditions to the spinoff will not be satisfied and/or that the spinoff will not be completed within the expected timeframe, on the expected terms or at all; the expected qualification of the spinoff as a tax-free transaction for U.S. federal income tax purposes, including whether or not an IRS ruling will be sought or obtained; the risk that any consents or approvals required in connection with the spinoff will not be received or obtained within the expected timeframe, on the expected terms or at all; risks associated with expected financing transactions undertaken in connection with the spinoff and risks associated with indebtedness incurred in connection with the spinoff; the risk that dis-synergy costs, costs of restructuring transactions and other costs incurred in connection with the spinoff will exceed estimates; and the impact of the spinoff on the businesses and the risk that the spinoff may be more difficult, time consuming or costly than expected, including the impact on resources, systems, procedures and controls, diversion of management's attention and the impact on relationships with customers, suppliers, employees and other business counterparties, general economic and business conditions, which will, among other things, affect demand for new residential and commercial construction; our inability to close the proposed acquisitions described in this presentation; our inability to achieve benefits from the acquisitions described in this presentation to offset the significant costs associated with the acquisitions; our ability to successfully identify, manage, and integrate additional acquisitions; the cyclical nature of, and changes in, the real estate and construction markets, including pricing changes by our competitors; governmental requirements and initiatives, including those related to mortgage lending or mortgage financing, funding for public or infrastructure construction, land usage, and environmental, health, and safety matters; disruptions, uncertainties or volatility in the credit markets that may limit our, our suppliers' and our customers' access to capital; our ability to successfully implement our operating strategy; weather conditions; our substantial indebtedness and the restrictions imposed on us by the terms of our indebtedness; the degree to which a pandemic will impact Knife River Holding Company which depends on future developments, including the resurgence of COVID-19 and its variants, federal and state mandates, actions taken by governmental authorities, effectiveness of vaccines being administered, and the pace and extent to which the economy recovers and remains under relatively normal operating conditions; our ability to implement cost containment strategies and the adverse effects of COVID-19 on our business, the economy and the markets we serve; our ability to maintain favorable relationships with third parties who supply us with equipment and essential supplies; our ability to retain key personnel and maintain satisfactory labor relations; and product liability, property damage, results of litigation, and other claims and insurance coverage issues. Readers are cautioned not to place undue reliance on forward-looking statements, which speak only as of the date hereof. We undertake no obligation to publicly update or revise any forward-looking statements after the date they are made, whether as a result of new information, future events or otherwise, except as required by federal securities laws. This presentation should be read along with the historical financial statements of Knife River Holding Company, including the most recent audited financial statements. Historical results may not be indicative of future results. This presentation contains certain financial information defined as "non-GAAP financial measures" by the Securities and Exchange Commission. These measures may be different from non-GAAP financial measures used by other companies and should not be considered in isolation or as a substitute for revenue, net income, operating income, cash flows from operating, investing or financing activities, or any other measure calculated in accordance with U.S. GAAP. Management believes these non-GAAP financial measures are useful to investors by providing meaningful information about operational efficiency compared to Knife River Holding Company's peers by excluding the impacts of differences in tax jurisdictions and structures, debt levels and capital investment. Knife River Holding Company's management uses the non-GAAP financial measures in conjunction with GAAP results when evaluating the company's operating results internally and calculating compensation packages. Non-GAAP financial measures are not standardized; therefore, it may not be possible to compare such financial measures with other companies' non-GAAP financial measures having the same or similar names. Knife River Holding Company strongly encourages investors to review the consolidated financial statements in their entirety and to not rely on any single financial measure. KNIFE RIVER 2#3Agenda Section Welcome and Introductions Knife River's EDGE Long-Term Value Creation Plan Speakers Dave Goodin President and Chief Executive Officer of MDU Resources Brian Gray President and Chief Executive Officer Life at Knife: Our Core Values Environment, Social, and Governance Sarah Stevens Director of Human Resources Break Financial Results and Outlook Nathan Ring Chief Financial Officer Closing Remarks Q&A KNIFE RIVER Brian Gray President and Chief Executive Officer Glenn Pladsen VP of Support Services 3#4KNIFE RIVER KNIFE RIVER WELCOME AND INTRODUCTIONS#5Knife River as an Independent Public Company EXECUTION Enhanced focus and accountability KNF Strategic flexibility for FLEXIBILITY long-term value creation CAPITAL ALLOCATION Disciplined and optimized capital allocation MANAGEMENT Highly qualified executive team average experience of 26 years KNIFE RIVER - Our Values People BOARD Dedicated and experienced Board Safety - Quality Environment KNIFE RIVER LO 5#6Highly Qualified Board of Directors EXPERIENCED AND DIVERSE BOARD Karen Fagg (Chair) Former Vice President of DOWL HKM; Former Chair, CEO, and majority owner of HKM Engineering Inc. Brian Gray President and CEO of Knife River KNIFE RIVER German Carmona Alvarez Global President of Applied Intelligence at Wood PLC Patricia Moss Former Vice Chair, President, and CEO of Cascade Bancorp and Bank of the Cascades Thomas Everist Chair and President of The Everist Company William Sandbrook Chairman and Co-CEO of Andretti Acquisition Corp.; Former Chair, President, and CEO of U.S. Concrete CO 6#7Experienced Board and Strong Governance Practices Board and governance practices establish a framework to ensure the effective oversight of strategic objectives following Knife River's separation from MDU Resources Board and Governance Practices Highly qualified directors with deep institutional, industry, and market knowledge Diverse Board, including by gender and race/ethnicity (together, 50%), as well as by geography Separate Chair and CEO Fully independent Board, excluding our CEO Majority vote standard for directors in uncontested elections ✓ Structure in place to fully declassify the Board at the 2027 annual meeting Standard proxy access provision ✓ Planned extensive and proactive shareholder engagement program to facilitate year-round dialogue KNIFE RIVER 7#8Long-Tenured Leadership Team With Exceptional Industry Knowledge STRONG, EXPERIENCED MANAGEMENT TEAM Brian Gray President and Chief Executive Officer 30 years at Knife River Former President of Knife River's Northwest segment from 2012-2022 Nathan Ring Vice President and Chief Financial Officer 20+ years at Knife River and MDU Resources Former Vice President of Business Development from 2017-2022 Trevor Hastings Vice President and Chief Operating Officer 27+ years at Knife River and MDU Resources Former President and CEO of WBI Energy, an MDU Resources subsidiary, since 2017 John Quade Vice President of Business Development " 28+ years at Knife River and MDU Resources Former President of Knife River's North Central segment from 2012-2023 Karl Liepitz Vice President, Chief Legal Officer, and Secretary 19+ years at MDU Resources Former Vice President, General Counsel, and Secretary of MDU Resources Nancy K. Christenson Vice President of Administration 45+ years at Knife River and MDU Resources Former Vice President of Administration, since 2009, and Vice President / Chief Accounting Officer from 2003-2009, amongst other accounting roles at the company Glenn Pladsen Vice President of Support Services 16+ years at Knife River and MDU Resources Former Director of Information Technology at Knife River, and led capital budgeting process and national account programs, amongst multiple other roles at the company Marney Kadrmas Chief Accounting Officer 23+ years at Knife River Former controller for the Northwest Segment and former Director of Accounting KNIFE RIVER 8#9MASABA MAGNUM TELESCOPINE CONVEYOR KNIFE RIVER'S EDGE: LONG-TERM VALUE CREATION PLAN#10Our History of Execution and Growth 1992: Acquired first aggregate site 2022: Announced spin off from MDU Resources 2008: Introduced Knife River branding 2023: Future of Independent Knife River Build to Scale 1992-2007 Operational Excellence 2008 - 2017 Sustainable Growth 2018-2022 EDGE 2023 + Expanded from 1 to 13 additional states with an emphasis on high-growth regional markets across western and central U.S. Achieved operational efficiencies by leveraging corporate scale, know-how and a vertically integrated business model Revitalized M&A with greater emphasis on people, environment and sustainability Competitive EDGE designed to create substantial value for shareholders Number of Acquisitions 65 ROIC Expansion1 ~1,140 bps 5-Year Average Adj. EBITDA Margin² 11.6% Adj. EBITDA Margin ~15% by 2025 20%+ Long-term Note: EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. 1 ROIC calculated as Operating Income / (Average Equity + Average Debt); 2 Reflects average of 2018-2022 Pro Forma Adjusted EBITDA. KNIFE RIVER 10#11Framework for Long-Term Shareholder Value Creation E D EBITDA Margin Improvement Discipline G I Growth Excellence EDGE 2025 Expectations Strong and Balanced Revenue Growth Increasing Mix of Aggregates Attractive Cash Flow Generation CF growth in-line with Adj. EBITDA growth Significant Adj. EBITDA Margin Expansion -15% by 2025 Sustain/Improve Industry-Leading ROIC 3-Year Avg. ROIC 12.9%1 Increasing Aggregate Mix Long-term Vision 20%+ Adj. EBITDA Margin No. 1 in Markets of Operation² Note: EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. 1 Reflects average ROIC 2020-2022; 2 Based on a proprietary assessment of volume in core market areas. KNIFE RIVER 11#12Today's Key Messages 1 Established company that is well positioned for profitable growth in an attractive industry 2 Aggregates-led, vertically integrated business model contributes to resiliency and industry- leading ROIC 3 Experienced leadership team with strong track record committed to executing EDGE strategy for margin improvement and long-term value creation 4 Unique culture and dedication to our values of People, Safety, Quality and Environment results in a cohesive team and competitive advantages KNIFE RIVER 12#13Attractive Industry with Structural Growth Drivers US AGGREGATES VOLUMES1 (in mmT) Total US Aggregates Volume 3,500 3,000 2,500 2,000 1,500 1,000 500 US AGGREGATES VALUES¹ (in mm USD) 100 $35,000 90 50 ≈ 8 0 2 2 2 2 Knife River Aggregates Volume $30,000 Total US Aggregates Value $25,000 $20,000 $15,000 $10,000 $5,000 $800 $700 $600 $500 $400 $300 $200 $100 Knife River Aggregates Revenue $- 2014 2018 2022 Knife River Aggregates Revenue 2002 2006 2010 2014 2018 2022 $- 2002 2006 2010 Total US Aggregates Production AGGREGATES INDUSTRY CHARACTERISTICS Knife River Aggregates Volume Total US Aggregates Production Value GROWTH DRIVERS ■ Essential to construction and infrastructure ■ Population growth Limited substitutes for high-quality aggregates ■ Gains in total employment ■ Localized production requirements ■ Increase in household formations ■ Fragmented industry with ~5,000 companies Additional housing stock and housing demand ■ Pricing strength over four decades and through recessions ■ Multi-year federal transportation and infrastructure investment tax receipts and supportive state tax receipts Note: 1 USGS National Minerals Information Center Annual Data -- Natural Aggregates Statistics and Information. KNIFE RIVER 13#14Further Upside from Approved Funding Amount for infrastructure Funding description INFRASTRUCTURE INVESTMENT AND JOBS ACT (IIJA) ~$1.2trn New funding ~$550bn of new infrastructure spending, with $350bn specific to roads and bridges Renewed funding ~$650bn of funding reauthorizations for Department of Transportation Funding allocations to Knife River states -$131bn of the total IIJA amount allocated to states where Knife River operates AMERICAN RESCUE PLAN ACT (ARPA) ~$194bn Total approved funding package $1.9trn in COVID-19 relief funding for states, schools and local governments Funding allocations to infrastructure $194bn allocated to U.S. states $340mm+ of funding dedicated to roadways and bridges STATE-LEVEL FUNDING 11 of the 14 states where Knife River operates have implemented new funding mechanisms for public projects Select examples " 2022: Texas Unified Transportation Program-$85bn Leading Idaho funding bill · $400mm Move Ahead Washington - $3bn ■ 2017: California Road Repair and Accountability Act - $54bn Keep Oregon Moving transportation funding package - $5.3bn Status Impact on Knife River Approved & Allocated Very High Approved & Allocated ✓ Approved & Allocated ✓ High Very High Source: White House, National League of Cities, American Society of Civil Engineers, U.S. Congress. KNIFE RIVER 14#15Leading Integrated Materials and Services Provider Strong Competitive Position in Attractive High Growth Mid-sized Markets Top 101 US aggregates producer Majority of Revenue from our No. 1 markets 2,3 75%+ of Aggregate Revenues 50%+ of Downstream Materials Revenues 70% of revenue from states growing faster than national average REVENUE MIX BY PRODUCT3,4 Northwest Mountain North Central Pacific All Other HQ Aggregate site (188 active sites)³ O Ready-Mix plant (101 total plants)³ Asphalt plant (56 total plants)³ £ 3 Other 13% Contracting Services 38% Aggregates 16% Ready-Mix Concrete 19% 3 Asphalt 14% Note: Source: USGS; 2 Based on a proprietary assessment of volume in core market areas; ³ As of 12/31/2022; 4% of 2022 Gross Revenue. KNIFE RIVER 15#16Strong Presence in Attractive High-Growth Markets 10-YR POPULATION CAGR OF STATES THAT KNIFE RIVER OPERATES IN ('12-'22) 10-YR GROSS STATE PRODUCT2 CAGR ('11-'21) State '12-'22 population CAGR1 % of 2022 gross revenue 3.0% Idaho 2.0% 11% Texas 1.4% 7% 2.1% 1.6% Washington 1.2% Montana 1.1% 6% Comprises ~70% of total North Dakota 1.0% gross 3% revenue South Dakota 0.9% 4% Oregon 0.8% 23% Knife River states avg. U.S. national avg. Non-Knife River states avg. Minnesota 0.6% 16% 10-YR CONSTRUCTION INDUSTRY³ CAGR ('11-'21) Nebraska 0.6% 1 Iowa 0.4% 9% 2.6% Hawaii 0.3% 6% 2.1% 1.8% California 0.3% 10% Wyoming 0.1% 3% Alaska 0.0% 2% I | U.S. national 0.6% average Knife River states avg. U.S. national avg. Non-Knife River states avg. Source: U.S. Census Bureau, IHS Markit and Federal Reserve Economic Data (FRED). Note: 1 Knife River weighted-average equal to 0.8%; 2 Represents the total monetary value of all finished goods and services produced within a state's borders; 3 Represents the monetary value of all finished goods and services produced in the construction industry within a state's borders. KNIFE RIVER 16#17Regional Overview Pacific Northwest Mountain North Central All Other1 Company KNIFE RIVER 2022 Revenue $469 MM $600 MM $542 MM $608 MM $353 MM $2,535 MM Business Mix 23% 37% 44% 43% 000 57% 63% 56% 18% 0 77% Materials Contracting Services 2022 EBITDA Margin 11.9% 3-yr Avg. EBITDA 15.0% Margin 38% 82% 62% 17.3% 13.4% 10.7% 2.7% 11.7%² 17.4% 12.9% 12.1% 4.6% 12.4%² Note: EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. Revenue represents 2022 revenue and business mix represents 2022 revenue mix before intersegment eliminations. Pie chart numbers are rounded and may not sum to 100%. 1 All Other segment consists of Energy Services, Texas and corporate services; 2 Pro Forma Adjusted EBITDA. KNIFE RIVER 17#18Differentiated Strategy for Attractive Returns and Profitable Growth RESERVES I BUSINESS STRATEGY VERTICAL INTEGRATION CHOICE OF MARKETS ✓ High quality reserves in key fast- growing markets ✓ Well-placed to benefit from expected structural growth, with additional upside from allocated funding dollars ✓ We are a 'vendor of choice' because of our ability to deliver end-to-end ✓ Integration ensures high reliability in our supply chain, making us a highly dependable partner for complex projects ✓ Mid-sized, high-growth markets ✓ Targeted investment in adjacencies to create and strengthen market- leading position ✓ Increasing scale and vertical integration strengthens competitive positioning UNIQUE CROSS-SECTIONAL COMPETENCIES RESILIENCE ACROSS CYCLES EXECUTION IMPACTFUL CULTURE WELL-DEFINED PATH TO DELIVERING ON THE EDGE PLAN FINANCIAL OUTCOMES AND LONG-TERM VALUE CREATION HIGH FLEXIBILITY AND VISIBILITY INDUSTRY-LEADING ROIC1 Note: 1 Peers used for comparison: Construction Partners, Granite Construction, Martin Marietta Materials, Summit Materials, Tutor Perini, Vulcan Materials. KNIFE RIVER STRONG BALANCE SHEET 18#19Creating Value Through Vertical Integration Aggregates (16%) Strategic high-quality reserves in key markets with above average population growth ■ 75%+ of revenues from markets where we have No. 1 share¹ Leading operational and logistics capabilities with internal transportation network Strategic storage and distribution capacity in select markets Upstream Materials (13%) Strong, reliable relationships with suppliers Downstream Leading market positions with internal proprietary expertise that ensure reliable quality and sourcing ■ No. 1 positioning in 21 ready-mix concrete and asphalt key markets1 Reliable supply of high- quality materials and services, a key competitive advantage Materials (33%) ■ Operational and logistics capabilities with internal transportation network Contracting Services (38%) Flexible operations with access to a broad network of roads through portable equipment Resilient with majority exposure to public customers Reliable internal supply chain of high-quality materials Unique ability to flexibly shift between public/private customers, job size and complexity Reliable demand pull- through for our materials, a key element of resilience Note: % of 2022 Revenue. 1 Based on a proprietary assessment of volume in core market areas. KNIFE RIVER BBB 19#20Diversified, Resilient, and Flexible with Attractive ROIC INCREASING SCALE AND MARKET LEADERSHIP FOR PROFITABLE GROWTH 2022 Revenue $2,535 MM 2022 EBITDA¹ 2022 Backlog² $296 MM $819 MM 5-Year Revenue CAGR³ 5-Year EBITDA CAGR4 3-Year Average ROIC5 6.9% Geography North Central 26% All Other 13% Pacific 18% Mountain 21% Northwest 23% 10.5% Asphalt 14% Product Other 13% Contracting Services 38% 0 Ready- mix 19% Aggregates 16% 12.9% Customer Concentration Other 80% Top 15 customers 20% Note: Pie chart numbers are rounded and may not sum to 100%. EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. 1 Reflects Pro Forma Adjusted EBITDA; ² Contracting Services backlog; 3 Reflects revenue CAGR 2017-2022; 4 Reflects Pro Forma adjusted EBITDA CAGR 2017-2022; 5 Reflects average of 2020-2022 ROIC. ROIC calculated as Operating Income / (Average Equity + Average Debt Excluding Operating Leases). Knife River figures are post dis-synergies. KNIFE RIVER 20 20#21Framework for Long-Term Shareholder Value Creation D G EBITDA Margin Improvement Discipline Growth Excellence Price increases: Optimize value of high-quality products and services ■ Expand strategic benefit of integration and end-to-end capabilities Cost control: ■ Focused execution to deliver cost savings and efficiencies Divestitures: Improve or divest underperforming assets Focus and Commitment: Companywide focus on executing with urgency and accountability Capital allocation, investments and incentives aligned with strategic goals Institutionalized best practices and process improvements within a nimble owner-operator mindset ■ With integrity, driven to win at all aspects of our business Organic: ■Reinvest where we are getting our best returns to capitalize on market share Strengthen position through strategic acquisitions Acquisitions: Target mid-sized high growth markets Maintain best-in-class status: Leverage the advantages of our people-first culture Empower teams with high-quality training and education Achieve best-in-class status: Safety Sustainability ■ Retention Diversify workforce KNIFE RIVER 21#22Northwest Region Provides Proven Roadmap to Execute our EDGE Plan Execution of the pre-EDGE "PLAN-GROW-ENJOY" strategy led to rapid profitable growth and strong ROIs serving as an exemplary model for the EDGE plan EDGE - Key Expected Drivers: Deliver strong growth from newly completed state-of- the-art Spokane prestress manufacturing facility Improve margins and market share with increased automation and strategic pricing and process improvement Expand leadership on service, quality and price across all products/markets MOVING TOWARDS AN AGGREGATE-LED MATERIALS COMPANY³ Revenue1 EBITDA1 9.4% Revenue CAGR² $600.2 19.4% EBITDA CAGR² $103.9 $244.0 $17.6 H 2012 2022 EBITDA Margin increased from 7.2% in 2012 to 17.3% in 2022 2012 2022 4.0% 18.6% 2.1% Aggregates 580 bps Increase in Aggregates 39.8% 19.7% 17.9% 37.3% 13.8% 22.4% Asphalt Contracting Services Other Note: Pie chart numbers are rounded and may not sum to 100%. EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. Other includes merchandise, transportation services and other products that individually are not considered to be a major line of business for the segment. 1 Revenue and EBITDA figures in millions; 2 CAGR reflects 2012-2022; 3 Reflects gross revenue breakdown by materials, contracting services and other. Ο 24.4% Ready Mix KNIFE RIVER 22 22#23Tailwinds and Expected EDGE Drivers by Region 32.2% PACIFIC 2022 Revenue Mix1 16.2% O 22.8% 6.3% 22.5% Strong economic tailwinds: Aggregates Ready Mix Asphalt Contracting Services Other ■ Rebound in tourism to pre-COVID levels in Hawaii and increased military spending ■ Rebound in DOT, local municipality, and port spending in California Large airport and dam projects in Alaska EDGE - Key Expected Drivers: Execute mining improvements and operational efficiencies in 1 of only 3 large quarries in Oahu, Hawaii and Southern California Increase strategically located aggregate reserves throughout the region Implement best practices and operating expertise from Northwest prestress operations in Alaska 56.5% MOUNTAIN 2022 Revenue Mix¹ 12.8% O 16.4% Aggregates Ready Mix Asphalt Contracting Services 14.3% Other Strong economic tailwinds: ■ Idaho is one of the top 2 fastest growing states with population increase of 23% since 2010 ■ Treasure Valley seeing significant infrastructure project growth Bozeman has grown 94% since 2000 Housing demand remain strong in western Montana EDGE - Key Expected Drivers: Capitalize on being one of few vertically integrated contractors with full upstream capabilities and synergies Continue to execute on disciplined bid strategy with record backlog allowing for greater selectivity ■ Focus of PIT crews on aggregate production facilities ■ Execute on record backlog seeking opportunity to increase margins throughout and exceeding quality requirements that result in job bonuses Note: Pie chart numbers are rounded and may not sum to 100%. Other includes merchandise, transportation services and other products that individually are not considered to be a major line of business for the segment. 1 Reflects gross revenue breakdown by materials, contracting services and other. KNIFE RIVER 23 23#24Tailwinds and Expected EDGE Drivers by Region (Cont'd) 3.1% NORTH CENTRAL 2022 Revenue Mix¹1 11.9% O 43.9% Aggregates 19.6% Ready Mix Asphalt Contracting Services 21.5% Other Strong economic tailwinds: North Dakota is the fourth fastest growing state (2010- 2020) with population growth over 20% ■ Sioux Falls had a record year of building permit valuations in 2022 ■ The Bakken is getting busier and is a steady source of demand EDGE - Key Expected Drivers: New region president has brought renewed emphasis on bid strategies and to properly capitalize on our vertical integration capabilities 2018 acquisition of high-quality reserves in Sioux Falls market positions us for future growth ■ Increase exposure to aggregates and materials mix through targeted strategic partnerships to supply external contractors 46.8% ALL OTHER 2022 Revenue Mix¹ 13.4% O 14.9% 6.8% 18.1% Strong economic tailwinds: Aggregates Ready Mix Asphalt Contracting Services Other Population growth of ~16% in Texas over the past decade (2010-2020) has pressured infrastructure ■ Texas has one of the largest DOT budgets in the US Public work including those from State Highway departments insulates region from economic downturns EDGE - Key Expected Drivers: - Improve operating efficiencies and increase volumes from greenfield Honey Creek quarry which became operational in 2023 Utilize second unit train of aggregate cars for higher market share Leverage strong relationships, reputation for high quality and service to increase share in liquid asphalt All Other segment consists of Energy Services, Texas operations and corporate services Note: Pie chart numbers are rounded and may not sum to 100%. Other includes merchandise, transportation services and other products that individually are not considered to be a major line of business for the segment. 1 Reflects gross revenue breakdown by materials, contracting services and other. KNIFE RIVER 24#25EDGE: Key Value Creation Priorities ◉ Price Alignment Price increases to align with higher costs driven by inflation, and value of products & services Increase use of technology to be highly selective and sophisticated in bidding to optimize our vertically integrated business model Operational Improvement Regional strategic reviews to transfer best practices and deploy PIT Crews to reduce costs and improve productivity in materials ☐ Optimize overhead costs and benefit from scale Balanced and Profitable Growth Through Vertical Integration Increase aggregate revenue mix within vertically integrated business model Core Values ◉ Maintain 'Life at Knife' People-First Culture KNIFE RIVER 25#26NIFE RIVER IAK KNIFE RIVER LIFE AT KNIFE: OUR CORE VALUES ENVIRONMENT, SOCIAL, AND GOVERNANCE#27Experienced Leadership Committed to Core "Life at Knife" Values LIFE AT KNIFE CORE VALUES PEOPLE SAFETY QUALITY ENVIRONMENT Experienced Board of Directors People-First: "Life at Knife" Retention Diversity Recruitment Knife River Training Center ■ Commitment to team ■ Fleet Recognition ■ Management involvement Recruiting/retention advantage Product and Service Quality ■ Process Quality ■ Pride in workplace and equipment Recycling ■ Fuel conservation Carbon reporting EPDs Sustainability KNIFE RIVER 27#28People-First Company LIFE AT KNIFE "Life at Knife" is our common language and how we live our values People-first means success depends on each other Coaching philosophy ■ Care ◉ Communication ▪ Consistency ■ Challenge ■ Commitment ■ Culture Communicating "My Life at Knife" discussions Life at Knife app Employee Survey 2017 Category 2021 (Pre "Life at Knife") Communications 68% 78% Engagement 77% 93% Culture 88% 92% KNIFE RIVER NIFE AN MOU RESOURCES COM A KNIFE RIVER YER H 28#29Retention: Competitive Advantage LOWER TURNOVER LEADS TO HIGHER PRODUCTIVITY Annualized Knife River US Total Private Mining/Logging Construction Turnover by Year 2017 31% 43% 48% 48% 62% 2018 31% 44% 49% 55% 58% 2019 30% 45% 50% 48% 65% 2020 28% 57% 63% 55% 69% 2021 33% 47% 52% 37% 56% 2022 32% 48% 52% 38% 53% Lower turnover rates than industry and US average LONGER TENURE SUPPORTS SAFETY AND QUALITY Median Tenure by Industry 5.7 5.7 5.7 5.2 3.9 3.7 Median Tenure by Occupation Knife River ■ US 15.8 8.1 6.2 4.7 4.9 4.6 3.9 3.1 Mining/Quarrying Source: BLS statistics. Construction Transportation and Utilities Management Professional Construction Transport and and related and extraction material moving Knife River median tenure 5.7 years, compared to 4.1 years for US labor force KNIFE RIVER 29 29#30Diversity and Recruitment MORE PERSPECTIVES, BETTER IDEAS, BETTER RESULTS One Team: Stronger Together Partnership with National Association of Minority Contractors Exceed AAP benchmarks Committing to disclose EEO-1 data Employees Knife River US Benchmark Females 11.9% 6.9% PHASE RIVIFE Minorities1 24.1% Exceeds all geographic area benchmarks Veterans 8.0% 5.4% Diversity Outreach Efforts April 2022-April 2023 1,700 Reached out directly over 1,700 times to organizations representing underrepresented individuals We are committed to promoting diversity and exceeding all benchmark goals KNIFE RIVER Source: OFCCP. Note: 1 OFCCP benchmark goals for minorities vary by geographic area. Knife River exceeds the AAP benchmark in each area we operate. 30 30#31Diversity and Recruitment (Cont'd) RECRUITMENT !!! Able to assemble best team possible hiring from strong applicant pool Hired 1,669 people in 2022; 420 in Q1 2023 KNIFE RIVER Life at Knife brand & social media promotion KNIFE RIVER Employee referral program Internships & Externships. Career Expos High school and trades promotion Training Center KNIFE RIVER 31#32Training CLASSROOM EDUCATION + HANDS-ON LEARNING KNIFE RIVER TRAINING CENTER 80,000ft² heated indoor 16,000ft² Accredited office, classroom Real-World Environment arena and lab facility CDL Training School Available to Third-Party Companies Increasing & Diversifying Construction Workforce ■ February 2022 - March 2023: 2,000+ people completed training; 3,500+ people attended events at the center KNIFE RIVER 32#33Commitments to Safety and Culture Our team is at the heart of everything we do. We invest in our employees with an active focus on safety. BUILDING A CULTURE OF SAFETY We invest in retaining and developing current employees, and recruiting new and diverse talent Focused on being an industry leader in safety and outperformed the industry by¹: RIR 18% LTAR 40% EMR 40% DOT incidents per million mile: 23% 3 Ts, Cardinal Rules, KR Cares Fleet safety - Top Drum & Top Wheel, telematics, cameras T TOOLS TRAINING TIME T Safety information is regularly reported to management and the Board Note: RIR: Recordable Incident Rate; LTAR: Lost Time Accident Rate; EMR: Experience Modification Rate. 1 Average of last three years, compared to BLS and FMCSA statistics. KNIFE RIVER 33 33#34Quality in All We Do QUALITY WORK IS A COMPETITIVE ADVANTAGE Product quality that meets/exceeds specifications and customer expectations Customer service Top Drum Program Construction equipment and trucks Plants and job sites Recruitment, onboarding, coaching, Life at Knife Recognition In 2022, received the Liberty Mutual Risk Management Award - presented less than 20 times in its 100-year history Sample of 2022 achievements: South Dakota Ready Mix Concrete Association - 2022 Concrete Award of Excellence Quality in Construction Awards for Outstanding performance from the Minnesota Department of Transportation Asphalt Paving Association of Oregon Awards Asphalt Paving Association of Iowa Awards ■ New prestress facility is PCI (Precast/Prestressed Concrete Institute) certified ■ Idaho Department of Transportation - State Highway Projects Awards KNIFE RIVER 34 34#35Sustainability is Integrated into our Strategy Sustainable practices are closely integrated into our business strategy, driving competitive advantages and having a positive impact in the communities where we live and work. Recycling: Over last three years, recycled an average of 909,385 tons of asphalt per year, which conserves natural resources, uses less energy, and reduces waste disposal Water Management: Capture and recycle water used in aggregate processing and ready-mix washing Å Alternative Transportation: Reducing the use of on-road trucks by 100,000 truckloads per year through rail/barge Powered by Nature 100% Renewable Fuel- Renewable diesel Approximately 4mm gallons used in 2022 (18% of total gallons consumed). Estimate using 6mm gallons in 2023 KNIFE RIVER 8342301 SMIPE Pawered by Nature 35#36Sustainability Across the Supply Chain Supporting our industry partners on lower carbon solutions. 35447 A 982 CAT KNIFE CAT RIVER I Knife River invested in Blue Planet to VER Knife River partners with suppliers ■ Cement manufacturers producing type 1L cement Equipment manufacturers focused on hybrid construction equipment Renewable diesel becoming available Knife River partners with customers Developing Environmental Product Declarations (EPD) for ready-mix and asphalt products to support customers' goals of lower carbon construction. ■ EPDS aligned with Federal Buy Clean Initiative Knife River partners with investors Measuring and reporting Scope 1 and 2 emissions 2021 - Implemented processes and systems to capture carbon baseline data beginning in 2022 pursue commercial means of creating and marketing synthetic limestone, using Blue Planet. 2022 Captured and calculated Scope 1 & 2 emissions I sequestered carbon dioxide that will ultimately result in a net-zero or net-negative carbon footprint 2023 Engaged third-party audit firm to review data- capture processes and CO2e calculations of 2022 emissions 2024 - Expects to publish first Knife River Sustainability Report KNIFE RIVER 36#37KIFE RIER ENQUESO COMPY FINANCIAL RESULTS AND OUTLOOK#38Financial Highlights Track Record of Strong and Balanced Growth Resilient and Integrated Portfolio Across a Diversified Base of Operations Disciplined Capital Allocation Driving Growth and Long-term Value Creation Focused on Margin Expansion With Well-Defined Path To Achievement Compelling Guidance and Long-Term Targets KNIFE RIVER 38#39Track Record of Strong and Balanced Growth REVENUE ($MM) ADJ. EBITDA ($MM)² ■Revenue¹ Intercompany sales $3,129 $2,716 $2,729 $2,730 $287 $296 $278 $2,392 594 $240 526 551 501 466 $185 2,535 2,191 2,178 2,229 1,926 2018 2019 2020 2021 2022 CAPEX ($MM) $91 $174 $178 $154 $136 2018 2019 2020 2021 2022 2018 2019 2020 2021 2022 CASH FLOW ($MM)³ $94 $86 $151 $118 $104 2018 2019 2020 2021 2022 Note: EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. Historical adjusted EBITDA figures reduced by an assumed $17mm in annual dis-synergies. 1 Revenue amounts exclude internal sales; 2 Pro Forma Adjusted EBITDA: 3 Cash Flow defined as Adj. EBITDA - Capex (excluding acquisitions). KNIFE RIVER 39#40Vertically Integrated and Diversified Portfolio GROSS REVENUE MIX (2022) Geography Pacific 18% All Other 14% North Central 23% 0 Mountain 21% Asphalt 14% Ready-mix 19% Product Other 13% Northwest 23% Contracting services 38% Customer Concentration Other 80% Top 15 customers 0 Private 23% Revenue Mix¹ 0 20% Public 77% COMMENTARY ◉ ☐ Strong position in attractive high- ☐ growth mid-sized markets Integrated model makes us resilient through down cycles ■ No one customer is more than 5% of gross revenue Unique ability to flex between public and private work ■ Range of ~60% to ~90% public work since 2007 Aggregates 16% Note: Pie chart numbers are rounded and may not sum to 100%. 1 Based on contracting services only, 2022. KNIFE RIVER 40#41Designed for Resilience Across Cycles Strategically diversified customer base and business mix to ensure resilience through down cycles REVENUE GROWTH, PEAK TO TROUGH (2007-2012)1 EBITDA MARGIN, PEAK TO TROUGH (2007-2012)1 Knife River Peer Group Median Knife River Peer Group Median (18%) (23%) (38%) (43%) Peer Range (480)bps (760)bps (840)bps Peer Range (1,460)bps Source: Company filings. Peers used for comparison: Granite Construction, Martin Marietta Materials, US Concrete, Vulcan Materials (Excludes peers that were not public over this time period) Note: EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. If available used EBITDA or Adjusted EBITDA as reported by peers; and calculated for Knife River (Operating Income + DD&A), Granite Construction (Operating Income + DD&A + Restructuring charge), Vulcan Materials' 2007 revenue and Adjusted EBITDA are pro forma adjusted for acquisition of Florida Rock per company filings. 1 Figures represent the difference between peak and trough values for companies during the years 2007-2012. KNIFE RIVER 41#42Disciplined and Balanced Capital Allocation to Maximize Long-Term Value Creation Disciplined Investment for Sustainable Growth Organic Growth Inorganic Growth Portfolio Optimization Leverage & Liquidity Invest for growth to create or strengthen our leadership position in select markets ■ Invest in supplementing and growing high quality aggregate reserves (1.1bn tons currently) ■ Maintenance & Growth Capex 5-7% of revenue ■ Focused on growing Aggregates in overall revenue mix Highly selective acquisitions in target markets Expand footprint in Western and Central USA Target mid-sized high growth markets ■ Focused on growing Aggregates in overall revenue mix ■ Divest or swap assets to strengthen market position, build scale ◉ ■ Optimize/invest in assets to serve key adjacencies Continuously evaluate assets on a 'best-fit', 'best- owner' basis Target average net leverage of 2.5x Conservative balance sheet to support growth strategy and maintain financial flexibility through cycles Strong liquidity and prudent cash management $350mm revolver capacity to support business through seasonal needs KNIFE RIVER 42#43Established Framework for Investment EFFECTIVE ‘PLAYBOOK' FOR PROFITABLE GROWTH Disciplined Approach Focused on strategic, attractively valued acquisitions and investments for market leadership Returns Focus Prioritize acquisitions and investment to achieve high returns on invested capital Bottom-up Approach Utilize regional team to lead process for expansion and seamless platform integration under rigorous oversight from management RECENT ACQUISITIONS Sweetman Const.Co Sweetman (2018) Expanded into strong Sioux Falls area Added -55mm tons of aggregate reserves; 3 asphalt plants, 7 ready-mix plants, with a fleet of 61 ready-mix trucks Since acquisition, saw a 28% increase¹ in revenue and 20% increase1 in profitability RECENT INVESTMENTS Prestress (2023) ~$60mm invested Expanded market areas to Washington state Increased scale and efficiencies with existing prestress operations Best-in-class team delivered improved productivity across the division EMPLOYEES SAFETY B BAKER ROCK Baker Rock (2021)² ■ Significantly expanded presence in key strategic growth locations surrounding the Portland metro area Added 88mm tons of aggregate reserves; 4 asphalt plants Since acquisition, saw a 60% increase in revenue and 59% increase in profitability Honey Creek (2023) Note: Represents average of first four years of ownership from 2019-2022 2 Figures pertain to primary quarry site. KNIFE RIVER ~$63mm invested Added 50mm tons of aggregates reserves Replaces aggregates previously purchased from third parties Strategically important to serve Texas operations for strong market position 43#44Industry-Leading Returns on Invested Capital Disciplined capital allocation to sustain attractive industry leading ROICS 3-YEAR AVERAGE ROIC (2020-2022) Source: Company filings. 12.9% Knife River 10.5% 7.2% Peer Range Peer Group Median 2.7% Note: Peers used for comparison: Construction Partners, Granite Construction, Martin Marietta Materials, Summit Materials, Tutor Perini, Vulcan Materials. ROIC is calculated as Operating Income / (Average Equity + Average Debt Excluding Operating Leases). Knife River figures are post dis-synergies. KNIFE RIVER 44#45Overcoming Inflation & EDGE in Action ◉ Inflation has been a significant headwind for the industry Recent inflationary pressures have increased cost of raw materials by over 10% relative to historical average annual increases of ~3%, creating a material headwind to profitability Our actions to mitigate and overcome the impact of inflation include repricing to align with our new costs and value provided YEAR-OVER-YEAR CHANGE IN AVERAGE SELLING PRICE BY PRODUCT LINE 18% 19% 13% 9% 9% 9% 8% 7% 24% 33% 28% 17% 14% 10% 17% Q1'22 Q2'22 Q3'22 Q4'22 Q1'23 Aggregates ($ / ton) Ready-mix Concrete ($/ c.y.) Asphalt ($/ ton) KNIFE RIVER 45#46Overcoming Inflation & EDGE in Action (Cont'd) Our decisive actions have resulted in margins inflecting upward CONTRACTING SERVICES TOTAL BACKLOG ($MM) ◉ $778 $665 Q1'21 Q1'22 $959 Q1'23 CONSOLIDATED EBITDA MARGIN1 12.2% 9.5% Q4'20 Q4'21 12.5% Q4'22 Record Backlog in Q1 2023 and has increased by 23% y/y with a 2-year CAGR of 20% Backlog includes execution of our EDGE plan with our new pricing and targeted bid strategy The full impact of additional margin tailwinds from repriced contracting services backlog expected in 2H 2023 - 2024 ☐ Consolidated EBITDA margins have demonstrated strong upward momentum with Y/Y improvement through 2022-23 Q4 2022 margins were ~30 bps above Q4 2020 levels and ~300 bps higher than Q4 2021 While Q1 is our seasonally low quarter, margins continue to inflect upwards and were ~130 bps higher in Q1 2023 over Q1 2022 Further margin tailwinds from our new EDGE pricing and bid strategy Note: EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. 1 As reported EBITDA margins of revenue. KNIFE RIVER 46#47Reiterating Our 2023 Guidance KEY EXPECTED DRIVERS Price Strategy to Align with Costs and Value of Products/Services Operational Discipline - Targeted Bid Strategy, Cost Focus Select Infrastructure Tailwinds INCOME STATEMENT GUIDANCE REVENUE $2.5 BN-$2.7 BN EBITDA $300 MM $350 MM - CASH USAGE Record First Quarter Backlog of $959 MM CAPITAL EXPENDITURES $125 MM Note: EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. Reflects 2023 guidance as disclosed on 5/4/2023. KNIFE RIVER 47#48EDGE: Our 2025 Targets & Long-term Vision Adjusted EBITDA Margin Capex -15% 11.7% 2022 $178 MM EDGE: KEY NEAR-TERM DRIVERS Pricing Strategy Targeted Bid Strategy PIT Crew and Institutionalizing Best Practices ■ Benefit from Scale ■ Focus on Increasing Mix of Aggregates KNIFE RIVER 20% 2025 Guidance Long-Term Vision ~$170 MM 5-7% of Revenue KEY ASSUMPTIONS ■ Increasing mix of aggregates relative to 2022 Normal economic environment No further rapid rise in inflation ■ No material M&A 48#49McNeilus wwwwww KIVER ANHOU TESORCES COMPART KNIFE RIVER TEXAS BRM-8946 KONF RIVE AN MDU RESOURCES CO CLOSING REMARKS#50Today's Key Messages 1 Established company that is well positioned for profitable growth in an attractive industry 2 Aggregates-led, vertically integrated business model contributes to resiliency and industry- leading ROIC 3 Experienced leadership team with strong track record committed to executing EDGE strategy for margin improvement and long-term value creation 4 Unique culture and dedication to our values of People, Safety, Quality and Environment results in a cohesive team and competitive advantages KNIFE RIVER 50 50#51KNIFE RIVER KRNW-1 Q & A#52ELIVER APPENDIX#53Today's Speakers Dave Goodin President and Chief Executive Officer of MDU Resources Brian Gray President and Chief Executive Officer Sarah Stevens Director of Human Resources Glenn Pladsen VP of Support Services Nathan Ring Chief Financial Officer KNIFE RIVER 33 53#54Regional Presidents KNIFE RIVER Steve Essoyan Pacific 39+ yrs. Experience at Knife River Andy Cramer North Central 16+ yrs. Experience at Knife River Stratos Flanders Northwest 17+ yrs. Experience at Knife River Bob Kober All Other (South) 28+ yrs. Experience at Knife River David Zinke Mountain 20+ yrs. Experience at Knife River Bob Cheever All Other (Energy Services) 24+ yrs. Experience at Knife River 54#55Ongoing Disclosure for Transparent Execution AGGREGATES DISCLOSURES BY REGION OTHER יון Aggregate Reserves (tons) Number of Aggregate Sites Total Annual Aggregates Production Ready-Mix Plants Asphalt Plants Project Mix in Contracting Services Backlog AGGREGATES DISCLOSURES ON COMPANYWIDE BASIS CONCRETE Ton of Aggregates Sold Aggregates Average Selling Price Cubic Yards of Ready-mix Concrete sold KNIFE RIVER ASPHALT Ready-mix Concrete Average Selling Price Tons of Asphalt Sold Asphalt Average Selling Price 55#56Regional Details PACIFIC REGION FINANCIAL PERFORMANCE NORTHWEST REGION FINANCIAL PERFORMANCE 2022 2020-2022 2022 2020-2022 Revenue $469mm 1.6% CAGR Revenue $600mm 20.1% CAGR Gross Margin 14.5% 17.2% AVG. Gross Margin 17.7% 18.4% AVG. EBITDA Margin 11.9% 15.0% AVG. EBITDA Margin 17.3% 17.3% AVG. REVENUE MIX (2022)1 REVENUE MIX (2022)1 32.2% 16.2% 22.8% 6.3% Aggregates Ready Mix Asphalt 22.5% Contracting Services Other 37.3% 2.1% 24.4% O Aggregates Ready Mix Asphalt Contracting Services 22.4% Other 13.8% Note: Pie chart numbers are rounded and may not sum to 100%. EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. Other includes merchandise, transportation services and other products that individually are not considered to be a major line of business for the segment. 1 Reflects gross revenue breakdown by materials, contracting services and other. KKNIFE RIVER 56#57Regional Details (Cont'd) MOUNTAIN REGION FINANCIAL PERFORMANCE NORTH CENTRAL REGION FINANCIAL PERFORMANCE 2022 2020-2022 2022 2020-2022 Revenue $542mm 9.6% CAGR Revenue $608mm 3.2% CAGR Gross Margin 14.3% 14.3% AVG. Gross Margin 11.8% 13.4% AVG. EBITDA Margin 13.4% 12.9% AVG. EBITDA Margin 10.7% 12.0% AVG. REVENUE MIX (2022)1 REVENUE MIX (2022)1 3.1% 11.9% 56.5% 12.8% 0 Aggregates 16.4% Ready Mix Asphalt Contracting Services 43.9% 14.3% Other 19.6% Aggregates Ready Mix Asphalt Contracting Services 21.5% Other Note: Pie chart numbers are rounded and may not sum to 100%. EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. Other includes merchandise, transportation services and other products that individually are not considered to be a major line of business for the segment. 1 Reflects gross revenue breakdown by materials, contracting services and other. KKNIFE RIVER 57#58Regional Details (Cont'd) ALL OTHER REGION FINANCIAL PERFORMANCE 2022 2020-2022 Revenue $353mm 4.1% CAGR Gross Margin 10.6% 13.0% AVG. EBITDA Margin 2.7% 4.6% AVG. REVENUE MIX (2022)1 46.8% 18.1% 13.4% Aggregates 14.9% Ready Mix Asphalt 6.8% Contracting Services Other Note: Pie chart numbers are rounded and may not sum to 100%. EBITDA, Adj. EBITDA and Cash Flow are non-GAAP measures, see Appendix for reconciliation. Other includes merchandise, transportation services and other products that individually are not considered to be a major line of business for the segment. 1 Reflects gross revenue breakdown by materials, contracting services and other. KKNIFE RIVER 58#59Non-GAAP Financial Guidance Our forward-looking guidance for EBITDA and Adjusted EBITDA Margin are non-GAAP financial measures that exclude or otherwise have been adjusted for special items from our U.S. GAAP financial statements. We are unable to reconcile forward-looking non-GAAP guidance measures to their nearest U.S. GAAP measure because we are unable to predict the timing of these adjustments with a reasonable degree of certainty. By their very nature, special and other non-core items are difficult to anticipate with precision because they are generally associated with unexpected and unplanned events that impact our company and its financial results. Therefore, we are unable to provide a reconciliation of the 2023 EBITDA and 2025 and long term Adjusted EBITDA Margin guidance. KNIFE RIVER 59#60Non-GAAP EBITDA Reconciliation Historical 2022 2022 2021 2020 2019 $72,916 $116,220 $129,755 $147,325 $120,371 (in thousands, except for margin values) Twelve Months Ended Dec 31, Net income Pro Forma 2018 $92,647 Adjustments: Income taxes 26,503 42,601 43,459 47,431 37,389 28,357 Depreciation, depletion and 117,798 117,798 100,974 89,626 77,450 61,158 amortization Interest 61,061 30,121 19,218 20,577 23,792 17,290 Consolidated EBITDA $278,278 $306,740 Revenues Net income margin $2,534,729 $2,534,729 $293,406 $2,228,930 $304,959 $2,178,002 $259,002 $199,453 $2,190,717 $1,925,854 2.9% 4.6% 5.8% 6.8% 5.5% 4.8% EBITDA margin 11.0% 12.1% 13.2% 14.0% 11.8% 10.4% Consolidated EBITDA 278,278 306,740 293,406 304,959 259,002 199,453 Stock-based Compensation Expense 4,098 2,644 3,637 3,357 1,857 1,266 Unrealized (gains) losses on Benefit 4,029 4,029 (2,294) (4,026) (3,639) 1,249 Plan Investments Dis-synergy costs (16,991) (16,991) (16,991) (16,991) (16,991) One-time spin related costs¹ 10,018 -- Adjusted EBITDA $296,423 $296,423 $277,759 $287,300 $240,229 $184,976 Net income margin 2.9% 4.6% 5.8% 6.8% 5.5% 4.8% Adjusted EBITDA margin 11.7% 11.7% 12.5% 13.2% 11.0% 9.6% Note: Totals may not sum due to rounding. 1 One-time spin related costs are borne by Knife River and are not inclusive of the total MDU Resources spin related costs. KNIFE RIVER 60 60#61Non-GAAP Cash Flow Reconciliation (in thousands) Twelve Months Ended Dec 31, Adjusted EBITDA Capital Expenditure Cash Flow Note: Totals may not sum due to rounding. KNIFE RIVER Pro Forma Historical 2022 2022 2021 2020 2019 2018 $296,423 $296,423 $277,759 $287,300 $240,229 $184,976 178,162 178,162 174,229 135,860 154,260 90,613 $118,261 $118,261 $103,530 $151,440 $85,969 $94,364 61#62Non-GAAP Return On Invested Capital (ROIC) Reconciliation Historical (in thousands, except for ROIC value) Twelve Months Ended Dec 31, 2022 2021 2020 Operating Income 194,295 191,077 214,498 Dis-synergy costs (16,991) (16,991) (16,991) Operating Income post dis-synergies $177,304 $174,086 $197,507 990,717 915,592 828,210 Average Shareholder's Equity 684,740 543,049 402,871 Average Debt (ex. operating leases) Average Invested Capital $1,675,457 $1,458,640 $1,231,080 ROIC Note: Totals may not sum due to rounding. KNIFE RIVER 10.6% 11.9% 16.0% 62 62