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For the quarterly period ended March 31, 2026

For the transition period from _____________ to ______________

Commission file number 1-41642

(Exact name of registrant as specified in its charter)

1150 West Century Avenue

P.O. Box 5568

Bismarck, North Dakota 58506-5568

(Address of principal executive offices)

(Zip Code)

(701) 530-1400

(Registrant's telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐.

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐.

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒.

Indicate the number of shares outstanding of each of the issuer's classes of common stock, as of April 30, 2026: 56,753,855 shares.

Unless otherwise stated or the context otherwise requires, references in this report to “Knife River,” the “Company,” “we,” “our,” or “us” refer to Knife River Corporation and its consolidated subsidiaries.

Knife River is an aggregates-based, vertically integrated construction materials and contracting services company with 1.3 billion tons of aggregate reserves as of December 31, 2025. About 35 percent of these aggregates support internal production of ready-mix concrete, asphalt, and various contracting services, including heavy-civil and concrete construction. Our company targets mid-size, higher-growth markets and is dedicated to growth and stakeholder value through our core values: People, Safety, Quality, and the Environment.

We supply construction materials and contracting services in the United States and operate across 15 states, mainly serving public-sector infrastructure projects like highways and bridges. Our access to high-quality aggregates supports our vertically integrated model, allowing us to share resources and maximize efficiency. Products are transported by truck, rail, or barge, depending on the market. Strategically located aggregate sites, plants, and a large fleet help us serve customers effectively. This integrated approach provides scale, efficiency, and operational excellence, benefiting customers, shareholders, and communities.

Our business is organized into four operating segments, each of which is also a reportable segment. Three of the reportable segments are aligned by key geographic areas, West, Mountain and Central. Each geographic segment offers a vertically integrated suite of products and services, including aggregates, ready-mix concrete, asphalt and contracting services. The Energy Services segment, which has locations throughout our geographic footprint, produces and supplies liquid asphalt and related services, primarily for use in asphalt road construction. For more information on our business segments, see Note 15 of the Notes to Consolidated Financial Statements.

At Knife River, we are a people-first construction materials and contracting services company. We provide construction materials and contracting services to build safe roads, bridges, airport runways and other critical infrastructure needs that connect people with where they want to go and with the supplies they need. We are one of the leading providers of crushed stone and sand and gravel in the United States and operate across 15 states. We conduct our operations through four reportable segments: West, Mountain, Central and Energy Services.

The accompanying consolidated interim financial statements were prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Interim financial statements do not include all disclosures provided in annual financial statements and, accordingly, these financial statements should be read in conjunction with the Company's 2025 Annual Report on Form 10-K (Annual Report). The information is unaudited but includes adjustments that are, in the opinion of management, necessary for a fair presentation of the accompanying consolidated interim financial statements and are of a normal recurring nature.

All revenues and costs, as well as assets and liabilities, directly associated with our business activities are included in the consolidated financial statements. General corporate expenses are included in the Consolidated Statements of Operations within selling, general and administrative expenses and other income.

On March 7, 2025, we acquired Strata Corporation (Strata), a leading construction materials and contracting services provider in North Dakota and northwestern Minnesota. The purchase price for Strata totaled $454.0 million and was subject to post-closing adjustments. The results of operations and balance sheet accounts for Strata are included in the consolidated financial statements from the date of acquisition.

In December 2025, we reclassified our retention receivables of $42.8 million on a contract-by-contract basis from accounts receivable. The reclassification resulted in an increase to contract assets of $31.8 million and a decrease to contract liabilities of $11.0 million. This reclassification was due to FASB’s clarification of retention receivables under ASC 606 and was applied on a prospective basis. Prior years quarters were not revised.

Management has also evaluated the impact of events occurring after March 31, 2026, up to the date of issuance of these consolidated interim financial statements on May 5, 2026, that would require recognition or disclosure in the Consolidated Financial Statements.

For all periods, the audited consolidated financial statements were prepared in accordance with GAAP and include the accounts of Knife River and our wholly owned subsidiaries. All intercompany accounts and transactions between our businesses have been eliminated in the accompanying audited consolidated financial statements.

The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities, at the date of the consolidated financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Estimates are used for items such as long-lived assets and goodwill; fair values of acquired assets and liabilities under the acquisition method of accounting; aggregate reserves; property depreciable lives; tax provisions; revenue recognized using the cost-to-cost measure of progress for contracts; expected credit losses; environmental and other loss contingencies; costs on contracting services contracts; actuarially determined benefit costs; asset retirement obligations; present value of right-of-use assets and lease liabilities; and the valuation of stock-based compensation. These estimates are based on management’s best knowledge of current events, historical experience, actions that we may undertake in the future and on various other assumptions that are believed to be reasonable under the circumstances. As additional information becomes available, or actual amounts are determinable, the recorded estimates are revised. Consequently, operating results can be affected by revisions to prior accounting estimates.

We consider all highly liquid investments with an original maturity of three months or less, when purchased, to be cash and cash equivalents. Restricted cash represents deposits held by our captive insurance company that is required by state insurance regulations to remain in the captive insurance company. Cash, cash equivalents and restricted cash on the Consolidated Balance Sheets is comprised of:

Some of our operations are seasonal and revenues from, and certain expenses for, such operations may fluctuate significantly among quarterly periods, with lower activity in the winter months and higher activity in the summer months. Accordingly, the interim results for particular segments, and for Knife River as a whole, may not be indicative of results for the full fiscal year or other future periods.

The following table provides a brief description of the accounting pronouncements applicable to us and the potential impact on our consolidated financial statements and/or disclosures:

Receivables consist primarily of trade and contract receivables for the sale of goods and services net of expected credit losses. A majority of our receivables are due in 30 days or less. The total balance of receivables past due 90 days or more was $23.2 million, $27.3 million and $15.3 million at March 31, 2026, March 31, 2025 and December 31, 2025, respectively. Receivables were as follows:

Our expected credit losses are determined through a review using historical credit loss experience; changes in asset specific characteristics; current conditions; and reasonable and supportable future forecasts, among other specific account data, and is performed at least quarterly. We develop and document our methodology to determine our allowance for expected credit losses. Risk characteristics used by management may include customer mix, knowledge of customers and general economic conditions of the various local economies, among others.

Specific account balances are written off when management determines the amounts to be uncollectible. Management has reviewed the balance reserved through the allowance for expected credit losses and believes it is reasonable.

Details of our expected credit losses were as follows:

Inventories on the Consolidated Balance Sheets were as follows:

Inventories are valued at the lower of cost or net realizable value using the average cost method. Inventories include production costs incurred as part of our aggregate mining activities. These inventoriable production costs include all mining and processing costs associated with the production of aggregates. Stripping costs incurred during the production phase, which represent costs of removing overburden and waste materials to access mineral deposits, are a component of inventoriable production costs.

Basic net loss per share is computed by dividing net loss by the weighted average number of shares of common stock outstanding during the applicable period. Diluted earnings per share is computed by dividing net loss by the total of the weighted average number of shares of common stock outstanding during the applicable period, plus the effect of non-vested performance shares and restricted stock units. Our potentially dilutive securities have been excluded from the computation of diluted net loss per share as the effect would reduce the net loss per share and is considered antidilutive. Basic and diluted net loss per share are calculated as follows, based on a reconciliation of the weighted-average common shares outstanding on a basic and diluted basis:

			Three Months Ended
			March 31,
			2026			2025
			(In thousands, except per share amounts)
Net loss			$	(79,176)		$	(68,710)
Weighted average common shares outstanding - basic			56,710			56,626
Effect of dilutive performance shares and restricted stock units			—			—
Weighted average common shares outstanding - diluted			56,710			56,626
Shares excluded from the calculation of diluted loss per share			173			274
Net loss per share-basic			$	(1.40)		$	(1.21)
Net loss per share-diluted			$	(1.40)		$	(1.21)

Comprehensive income (loss) is comprised of net income (loss) and other comprehensive income (loss). The only component of other comprehensive income (loss) is the amortization of postretirement liability losses for our benefit plans. As of March 31, 2026 and 2025, and December 31, 2025, accumulated other comprehensive loss was $10.1 million, $9.2 million and $10.3 million, respectively.

For the three months ended March 31, 2026 and 2025, we amortized $127,000 and $63,000, respectively, of expense into other income, and $41,000 and $20,000, respectively, into income taxes.

Revenue is recognized when a performance obligation is satisfied by transferring control over a product or service to a customer. Revenue includes revenue from the sales of construction materials and contracting services. Revenue is measured based on consideration specified in a contract with a customer and excludes any sales incentives and amounts collected on behalf of third parties. We are considered an agent for certain taxes collected from customers. As such, we present revenues net of these taxes at the time of sale to be remitted to governmental authorities, including sales and use taxes. Revenue for construction materials is recognized at a point in time when delivery of the products has taken place. Contracting services revenue is recognized over time using an input method based on the cost-to-cost measure of progress on a project.

In the following tables, revenue is disaggregated by category for each segment and includes sales of materials to both third parties and internal customers. Due to consolidation requirements, the internal sales revenues must be eliminated against the construction materials product used in downstream materials and contracting services to arrive at the external operating revenues. We believe this level of disaggregation best depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. For more information on the Company’s reportable segments, see Note 15.

The timing of revenue recognition may differ from the timing of invoicing to customers. The timing of invoicing to customers does not necessarily correlate with the timing of revenues being recognized under the cost-to-cost method of accounting. Contracts from contracting services are billed as work progresses in accordance with agreed upon contractual terms. Generally, billing to the customer occurs contemporaneous to revenue recognition. A variance in timing of the billings may result in a contract asset or a contract liability. A contract asset occurs when revenues are recognized under the cost-to-cost measure of progress, which exceeds amounts billed on uncompleted contracts. Such amounts will be billed as standard contract terms allow, usually based on various measures of performance or achievement. A contract liability occurs when there are billings in excess of revenues recognized under the cost-to-cost measure of progress on uncompleted contracts. Contract liabilities decrease as revenue is recognized from the satisfaction of the related performance obligation.

The changes in contract assets and liabilities were as follows:

1Following the issuance of the FASB Staff Educational Paper on Topic 606: Presentation and Disclosure of Retainage for Construction Contractors, we have reclassed retention receivables on a contract-by-contract basis from accounts receivable to contract assets and liabilities. The change in presentation was on a prospective basis beginning with balances as of December 31, 2025.

We recognized $27.6 million in revenue for the three months ended March 31, 2026, which was previously included in contract liabilities at December 31, 2025. We recognized $28.2 million in revenue for the three months ended March 31, 2025, which was previously included in contract liabilities at December 31, 2024.

We recognized a net increase in revenues of $4.2 million and $8.0 million for the three months ended March 31, 2026 and 2025, respectively, from performance obligations satisfied in prior periods.

The remaining performance obligations, also referred to as backlog, include unrecognized revenues that we reasonably expect to be realized. These unrecognized revenues can include: projects that have a written award, a letter of intent, a notice to proceed, an agreed upon work order to perform work on mutually accepted terms and conditions, and change orders or claims to the extent management believes additional contract revenues will be earned and are deemed probable of collection. The majority of our contracts for contracting services have an original duration of less than one year.

At March 31, 2026, our remaining performance obligations were $1.2 billion. We expect to recognize the following revenue amounts in future periods related to these remaining performance obligations: $913.9 million within the next 12 months or less; $155.3 million within the next 13 to 24 months; and $99.6 million in 25 months or more.

The following acquisitions were accounted for as business combinations in accordance with ASC 805 - Business Combinations. The results of the business combinations have been included in the Company's Consolidated Financial Statements beginning on the acquisition dates. Pro forma financial amounts reflecting the effects of the business combinations are not presented, as none of these business combinations, individually or in the aggregate, were material to our financial position or results of operations.

Acquisitions are also subject to customary adjustments based on, among other things, the amount of cash, debt and working capital in the business as of the closing date. The amounts included in the Consolidated Balance Sheets for these adjustments are considered provisional until final settlement has occurred.

As of March 31, 2026, the estimated fair value of the assets acquired and liabilities for the acquisitions completed in 2026 were considered provisional as we continue to gather information to finalize the valuation of these assets and liabilities. The fair values are considered provisional until final fair values are determined during the measurement period. We expect to record adjustments as we accumulate the information needed to estimate the fair value of assets acquired and liabilities assumed, including working capital balances, estimated fair value of identifiable intangible assets, property, plant and equipment, total consideration and goodwill. We will utilize market and cost approaches to estimate the fair value of the property, plant and equipment, excluding aggregate reserves. The fair value of aggregate reserves and intangible assets are determined using the income approach. All estimates, key assumptions, and forecasts were either provided by or reviewed by management. We have engaged third-party valuation firms to assist in the analysis and valuation of certain assets. While we chose to utilize third-party valuation firms, the fair value analysis and related valuations represent the conclusions of management and not the conclusions or statements of any third party.

The excess of the total purchase price over the fair value of assets acquired and liabilities assumed has been allocated to goodwill. We believe that the goodwill relates to several factors, including potential synergies related to market opportunities for multiple product offerings and economies of scale expected from combining our operations with the businesses acquired.

During the first three months of 2026, we completed the following three acquisitions:

•Two Montana aggregates-based operations within the Mountain segment; one operation consists of a ready-mix concrete business supported by owned aggregate reserves, while the other includes owned aggregate reserves, ready-mix operations and precast concrete manufacturing capabilities.

•A Utah aggregates-based company in the Mountain segment that consists of owned aggregate reserves, asphalt production and contracting services; this acquisition expanded our footprint into a new state.

The aggregated purchase consideration for these three acquisitions was $174.2 million, net of cash assumed, and subject to post-closing adjustments. These acquisitions were not considered material separately or in the aggregate. The acquisitions resulted in the recognition of $8.6 million of current assets; $120.8 million of assets in property, plant and equipment; $54.2 million of goodwill; $5.3 million of intangible assets, which included $4.1 million of backlog and $1.2 million of customer relationships; $8.5 million deferred income tax liability; $5.7 million of current liabilities; and $547,000 of noncurrent liabilities - other. The revenue and net income (loss) of these acquisitions was immaterial for the three months ended March 31, 2026.

During 2025, we completed five acquisitions with an aggregated purchase price of $622.2 million, subject to future post-closing adjustments. As of March 31, 2026, the purchase accounting was complete on three of the acquisitions and no material adjustments were needed. During the first quarter of 2026, we recorded a reduction to goodwill of $780,000, related to an increase of $3.0 million in intangibles and a decrease of $2.2 million in property, plant and equipment for acquisitions completed in 2025.

For the three months ended March 31, 2026 and 2025, we incurred acquisition-related costs on completed and other potential acquisitions of $2.0 million and $5.3 million, respectively. These costs are included in our Corporate Services in selling, general and administrative expenses on the Consolidated Statement of Operations.

On March 7, 2025, we sold four ready-mix plant operations for total proceeds of $14.5 million. The ready-mix plant operations were acquired by us as part of the Strata acquisition and subsequently sold to a third-party. The ready-mix plants were included in assets held for sale on the opening balance sheet for Strata at the time of the acquisition.

The changes in the carrying amount of goodwill were as follows:

Other amortizable intangible assets were as follows:

The previous tables include goodwill and intangible assets associated with the business combinations completed in 2026 and 2025. For more information related to these business combinations, see Note 10.

Amortization expense for amortizable intangible assets for the three months ended March 31, 2026 and 2025 was $3.1 million and $1.1 million, respectively. Estimated amortization expense for identifiable intangible assets as of March 31, 2026, was:

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the measurement date. The fair value guidance establishes a hierarchy for grouping assets and liabilities, based on the significance of inputs. The estimated fair values of the assets and liabilities measured on a recurring basis are determined using the market approach.

We measure our investments in certain fixed-income and equity securities at fair value with changes in fair value recognized in income. We anticipate using these investments, which consist of insurance contracts, to satisfy our obligations under our unfunded, nonqualified defined benefit and defined contribution plans for our executive officers and certain key management employees, and invest in these fixed-income and equity securities for the purpose of earning investment returns and capital appreciation. These investments, which totaled $35.7 million, $30.5 million and $34.0 million at March 31, 2026 and 2025, and December 31, 2025, respectively, are classified as investments on the Consolidated Balance Sheets. The net unrealized losses on these investments were $761,000 and $692,000 for the three months ended March 31, 2026 and 2025, respectively. The change in fair value, which is considered part of the cost of the plan, is classified in other income on the Consolidated Statements of Operations.

The Company's assets measured at fair value on a recurring basis were as follows:

Our Level 2 money market funds are valued at the net asset value of shares held at the end of the period, based on published market quotations on active markets, or using other known sources including pricing from outside sources. The estimated fair value of the Level 2 insurance contracts is based on contractual cash surrender values that are determined primarily by investments in managed separate accounts of the insurer. These amounts approximate fair value. The managed separate accounts are valued based on other observable inputs or corroborated market data.

Though we believe the methods used to estimate fair value are consistent with those used by other market participants, the use of other methods or assumptions could result in a different estimate of fair value.

We apply the provisions of the fair value measurement standard to our nonrecurring, non-financial measurements, including long-lived asset impairments. These assets are not measured at fair value on an ongoing basis but are subject to fair value adjustments only in certain circumstances. We review the carrying value of our long-lived assets, excluding goodwill, whenever events or changes in circumstances indicate that such carrying amounts may not be recoverable.

The assets and liabilities of the acquisitions that occurred through March 31, 2026 and 2025 were calculated using a market or cost approach. The fair value of some of the assets was determined based on Level 3 inputs including estimated future cash flows, discount rates, growth rates and sales projections, all of which require significant management judgment. For more information on these Level 2 and 3 fair value measurements, see Note 10.

Our long-term debt is not measured at fair value on the Consolidated Balance Sheets and the fair value is being provided for disclosure purposes only. The fair value was categorized as Level 2 in the fair value hierarchy and was based on discounted cash flows using current market interest rates. The estimated fair value of our Level 2 long-term debt was as follows:

The carrying amounts of our remaining financial instruments included in current assets and current liabilities approximate their fair values.

Certain debt instruments of ours contain restrictive covenants and cross-default provisions. In order to borrow under the debt agreements, we must be in compliance with the applicable covenants and certain other conditions, all of which management believes we, as applicable, were in compliance with at March 31, 2026. In the event we do not comply with the applicable covenants and other conditions, alternative sources of funding may need to be pursued.

Long-term Debt Outstanding Long-term debt outstanding was as follows:

Schedule of Debt Maturities Long-term debt maturities, which excludes unamortized debt issuance costs, at March 31, 2026, were as follows:

Cash expenditures for interest and income taxes were as follows:

Noncash investing and financing transactions were as follows:

We focus on the vertical integration of our products and services by offering customers a single source for construction materials and related contracting services. We operate in 15 states across the United States through our four operating segments: West, Mountain, Central and Energy Services, each of which is also a reportable segment. Each segment’s performance is evaluated based on segment results without allocating corporate expenses, which include corporate costs associated with accounting, legal, treasury, business development, information technology, human resources, and other corporate expenses that support the operating segments.

Three of our reportable segments are aligned by key geographic areas due to the production of construction materials and related contracting services and one is based on product line. Each segment is led by a segment manager who reports to our chief operating officer, who is also our chief operating decision maker, along with the chief executive officer. Our chief operating decision maker uses EBITDA to evaluate the performance of the segments, perform analytical comparisons to budget and uses historical and projected EBITDA to allocate resources, including capital allocations.

Each geographic segment offers a vertically integrated suite of products and services, including aggregates, ready-mix concrete, asphalt and contracting services, while the Energy Services segment produces and supplies liquid asphalt, primarily for use in asphalt road construction, and is a supplier to some of the other segments. Each geographic segment mines, processes and sells construction aggregates (crushed stone and sand and gravel); produces and sells asphalt; and produces and sells ready-mix concrete as well as vertically integrating its contracting services to support the aggregate-based product lines including heavy-civil construction, asphalt and concrete paving, and site development and grading. Although not common to all locations, the geographic segments also sell cement, merchandise and other building materials and related services.

Corporate Services represents the unallocated costs of certain corporate functions, such as accounting, legal, treasury, business development, information technology, human resources and other corporate expenses that support the operating segments. Corporate Services also includes an immaterial amount of external revenue from the Knife River Training Center. We account for intersegment sales and transfers as if the sales or transfers were to third parties. The accounting policies applicable to each segment are consistent with those used in the audited consolidated financial statements.

The preceding information follows the same accounting policies as described in the audited financial statements and notes included in the Company's 2025 Annual Report. Information on our segments was as follows:

We are party to claims and lawsuits arising out of our business and that of our consolidated subsidiaries, which may include, but are not limited to, matters involving property damage, personal injury, and environmental, contractual and statutory obligations. We accrue a liability for those contingencies when the incurrence of a loss is probable, and the amount can be reasonably estimated. If a range of amounts can be reasonably estimated and no amount within the range is a better estimate than any other amount, then the minimum of the range is accrued. We do not accrue liabilities when the likelihood that the liability has been incurred is probable, but the amount cannot be reasonably estimated or when the liability is believed to be only reasonably possible or remote. For contingencies where an unfavorable outcome is probable or reasonably possible and which are material, we disclose the nature of the contingency and, in some circumstances, an estimate of the possible loss. Accruals are based on the best information available, but in certain situations management is unable to estimate an amount or range of a reasonably possible loss, including, but not limited to, when: (1) the damages are unsubstantiated or indeterminate, (2) the proceedings are in the early stages, (3) numerous parties are involved, or (4) the matter involves novel or unsettled legal theories.

At March 31, 2026 and 2025, and December 31, 2025, we accrued contingent liabilities as a result of litigation, which have not been discounted, of $3.2 million, $3.4 million and $3.3 million, respectively. At March 31, 2026, we also recorded corresponding insurance receivables of $145,000. At March 31, 2025 and December 31, 2025, there were no corresponding insurance receivables recorded. The accruals are for contingencies, including litigation and environmental matters. Most of these claims and lawsuits are covered by insurance, thus our exposure is typically limited to our deductible amount. We will continue to monitor each matter and adjust accruals as might be warranted based on new information and further developments. Management believes that the outcomes with respect to probable and reasonably possible losses in excess of the amounts accrued, net of insurance recoveries, while uncertain, either cannot be estimated or will not have a material effect upon the Company's financial position, results of operations or cash flows. Unless otherwise required by GAAP, legal costs are expensed as they are incurred.

Knife River Corporation - Northwest is a party to claims for the cleanup of a superfund site in Portland, Oregon. There were no material changes to the environmental matters that were previously reported in the audited financial statements and notes included in our 2025 Annual Report.

We have outstanding obligations to third parties where we have guaranteed our performance. These guarantees are related to contracts for contracting services and certain other guarantees. At March 31, 2026, the fixed maximum amounts guaranteed under these agreements aggregated to $11.5 million, all of which have no scheduled maturity date. Certain of the guarantees also have no fixed maximum amounts specified. There were no amounts outstanding under the previously mentioned guarantees at March 31, 2026.

We have outstanding letters of credit to third parties related to insurance policies and other agreements. At March 31, 2026, the fixed maximum amounts guaranteed under these letters of credit aggregated to $51.8 million. At March 31, 2026, the amounts of scheduled expiration of the maximum amounts guaranteed under these letters of credit aggregate to $756,000 in 2026, $50.9 million in 2027, and $175,000 in 2028. There were no amounts outstanding under the previously mentioned letters of credit at March 31, 2026.

In the normal course of business, we have surety bonds related to contracts for contracting services, reclamation obligations and insurance policies of its subsidiaries. In the event a subsidiary of Knife River does not fulfill a bonded obligation, we would be responsible to the surety bond company for completion of the bonded contract or obligation. A large portion of the surety bonds are expected to expire within the next 12 months; however, we will likely continue to enter into surety bonds for our subsidiaries in the future. At March 31, 2026, approximately $990.4 million of surety bonds were outstanding, which were not reflected on the Consolidated Balance Sheet.

Forward-Looking Statements

This Quarterly Report on Form 10-Q contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended ("Exchange Act"). Forward-looking statements are all statements other than statements of historical fact, including without limitation those statements that are identified by the words "anticipates," "estimates," "expects," "intends," "plans," "predicts" and similar expressions, and include statements concerning plans, projections, objectives, goals, strategies, future events or performance, and underlying assumptions (many of which are based, in turn, upon further assumptions) and other statements that are other than statements of historical facts. From time to time, Knife River Corporation ("Knife River," the "Company," "we," "our," or "us") may publish or otherwise make available forward-looking statements of this nature, including statements related to its Competitive EDGE strategy (EDGE) implemented to improve margins and to execute on other strategic initiatives aimed at generating long-term profitable growth, shareholder value creation, expected long-term goals, expected backlog margin, acquisitions, financing plans, expected federal and state funding for infrastructure or other proposed strategies.

Forward-looking statements involve risks and uncertainties, which could cause actual results or outcomes to differ materially from those expressed. Our expectations, beliefs and projections are expressed in good faith and are believed to have a reasonable basis, including without limitation, management's examination of historical operating trends, data contained in our records and other data available from third parties. Nonetheless, our expectations, beliefs or projections may not be achieved or accomplished and changes in such assumptions and factors could cause actual future results to differ materially.

Any forward-looking statement contained in this document speaks only as of the date on which the statement is made, and we undertake no obligation to update any forward-looking statement or statements to reflect events or circumstances that occur after the date on which the statement is made or to reflect the occurrence of unanticipated events, except as required by law. New factors emerge from time to time, and it is not possible for management to predict all the factors, nor can it assess the effect of each factor on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statement. All forward-looking statements, whether written or oral and whether made by or on behalf of our Company, are expressly qualified by the risk factors and cautionary statements reported in the section entitled "Item 1A. Risk Factors" in Part I of the Company's 2025 Annual Report on Form 10-K (Annual Report) and subsequent filings with the United States Securities and Exchange Commission (SEC).

Company Overview

At Knife River, we are a people-first construction materials and contracting services company. We provide construction materials and contracting services to build safe roads, bridges, airport runways and other critical infrastructure needs that connect people with where they want to go and with the supplies they need. We also champion a positive workplace culture by focusing on safety, training, compensation and work-life balance.

We are one of the leading providers of crushed stone and sand and gravel in the United States and operate through four reportable segments across 15 states: West, Mountain, Central and Energy Services. The geographic segments primarily provide aggregates, asphalt and ready-mix concrete, as well as related contracting services such as heavy-civil construction, asphalt paving, concrete construction, site development and grading. The Energy Services segment produces and supplies liquid asphalt and related services, primarily for use in asphalt road construction.

As an aggregates-based construction materials and contracting services company, we have 1.3 billion tons of aggregate reserves supporting our vertically integrated business strategy. About 35 percent of these aggregates are used internally to support value-added downstream products like ready-mix concrete and asphalt, as well as contracting services such as heavy-civil construction, asphalt paving, concrete construction, bridges and in some segments the manufacturing of prestressed concrete products. Our strategically located aggregate sites and associated asphalt and ready-mix plants near mid-sized, higher-growth markets offer transportation advantages, enabling competitive pricing and higher margins. We serve both public and private markets, with public projects making up most of our work and providing stability through economic cycles, which helps offset the cyclical nature of the private markets.

We provide various products and services and operate a variety of facility types, including aggregate quarries and mines, ready-mix concrete plants, asphalt plants and distribution facilities, in the following states:

•West: Alaska, California, Hawaii, Oregon and Washington

•Mountain: Idaho, Montana, Utah and Wyoming

•Central: Iowa, Minnesota, North Dakota, South Dakota and Texas

•Energy Services: California, Iowa, Nebraska, Oregon, South Dakota, Texas, Washington and Wyoming

The following table presents a summary of products and services provided, as well as modes of transporting those products: