KNF / Knife River Corporation - Pengajuan SECLaporan Tahunan, Pernyataan Proksi

Knife River Corporation
US ˙ NYSE ˙ US4988941047

Mga Batayang Estadistika
CIK 1955520
SEC Filings
All companies that sell securities in the United States must register with the Securities and Exchange Commission (SEC) and file reports on a regular basis. These reports include company annual reports (10K, 10Q), news updates (8K), investor presentations (found in 8Ks), insider trades (form 4), ownership reports (13D, and 13G), and reports related to the specific securities sold, such as registration statements and prospectus. This page shows recent SEC filings related to Knife River Corporation
SEC Filings (Chronological Order)
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August 5, 2025 EX-95

Mine Safety Disclosures

KNIFE RIVER CORPORATION MINE SAFETY INFORMATION The Dodd-Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) requires issuers to include in periodic reports filed with the SEC certain information relating to citations or orders for violations of standards under the Federal Mine Safety and Health Act of 1977 (Mine Act), as amended by the Mine Improvement and New Emergency Response Act of 2006 (Mine Safety Act).

August 5, 2025 EX-10.3

Fifth Amendment to Knife River Corporation, 401(k) Retirement Plan, as amended June 30, 2025

krc401kplan5thamendment- -1- 182688815.1 FIFTH AMENDMENT TO KNIFE RIVER CORPORATION 401(k) RETIREMENT PLAN The Knife River Corporation 401(k) Retirement Plan (the “Plan”), as established effective May 1, 2023, is amended by this Fifth Amendment effective as of June 30, 2025. All terms defined in the Plan shall have the same meanings when used herein. All provisions of the Plan not amended by this

August 5, 2025 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 ☐ TRANSITION REPORT PURSUANT TO S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 1-41642 Knife River Corporation

August 5, 2025 EX-99

KNIFE RIVER CORPORATION REPORTS SECOND QUARTER 2025 FINANCIAL RESULTS Achieved record backlog Acquired two aggregates-led companies Unfavorable weather impacted start to the construction season

KNIFE RIVER CORPORATION REPORTS SECOND QUARTER 2025 FINANCIAL RESULTS Achieved record backlog Acquired two aggregates-led companies Unfavorable weather impacted start to the construction season BISMARCK, N.

August 5, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) August 5, 2025 Knife River Corpor

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) August 5, 2025 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identification

August 5, 2025 EX-10.2

Knife River Corporation, 401(k) Retirement Plan, as amended

FOURTH AMENDMENT TO KNIFE RIVER CORPORATION 401(k) RETIREMENT PLAN The Knife River Corporation 401(k) Retirement Plan (the “Plan”), as established effective May 1, 2023, is amended by this Fourth Amendment effective as of June 30, 2025.

August 5, 2025 EX-4.1

hereto as Guarantors, Knife River Corporation and U.S. Bank Trust Company, National Association

Third Supplemental Indenture THIRD SUPPLEMENTAL INDENTURE, dated as of June 12, 2025 (this “Supplemental Indenture”), by and among the parties that are signatories hereto as Guarantors (each, a “Guaranteeing Subsidiary” and together, the “Guaranteeing Subsidiaries”), Knife River Corporation, a Delaware Corporation (the “Issuer”), and U.

August 5, 2025 EX-10.1

rporation Director Com

KNIFE RIVER CORPORATION DIRECTOR COMPENSATION POLICY This Director Compensation Policy (the “Policy”) was adopted by the Board of Directors (the “Board”) of Knife River Corporation (the “Company”) on May 22, 2025, and is effective as of June 1, 2025.

June 12, 2025 11-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 11-K ý ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 o TRANSITION REPORT PURSUANT TO SECTION 15(

11-K 1 a2024form11-k.htm KNIFE RIVER CORPORATION FORM 11-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 11-K ý ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR o TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission f

May 28, 2025 8-K

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Material Modification to Rights of Security Holders, Financial Statements and Exhibits, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) May 22, 2025 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identification No

May 28, 2025 EX-3.1

Amended and Restated Certificate of Incorporation of Knife River Corporation

SECOND AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF KNIFE RIVER CORPORATION Knife River Corporation (the “Corporation”), a corporation organized and existing under the laws of the State of Delaware, pursuant to Sections 242 and 245 of the General Corporation Law of the State of Delaware, as it may be amended (the “DGCL”), hereby certifies as follows: 1.

May 28, 2025 EX-3.2

Amended and Restated Bylaws of Knife River Corporation

SECOND AMENDED AND RESTATED BYLAWS OF KNIFE RIVER CORPORATION These Second Amended and Restated Bylaws (these “Bylaws”) of Knife River Corporation, a Delaware corporation (the “Corporation”), are effective as of May 22, 2025 and hereby amend and restate the previous amended and restated bylaws of the Corporation in their entirety: ARTICLE 1 OFFICES AND RECORDS Section 1.

May 14, 2025 CORRESP

May 14, 2025

PO Box 5568 Bismarck, ND 58506-5568 Street Address: 1150 West Century Avenue Bismarck, ND 58506 (701) 530-1400 (701) 530-1451 Fax May 14, 2025 VIA EDGAR SUBMISSION Office of Energy & Transportation Division of Corporation Finance U.

May 6, 2025 EX-99

KNIFE RIVER CORPORATION REPORTS FIRST QUARTER 2025 FINANCIAL RESULTS Closed on acquisition of Strata Corporation On track for record full-year revenue, net income and adjusted EBITDA Updated full-year 2025 guidance

KNIFE RIVER CORPORATION REPORTS FIRST QUARTER 2025 FINANCIAL RESULTS Closed on acquisition of Strata Corporation On track for record full-year revenue, net income and adjusted EBITDA Updated full-year 2025 guidance BISMARCK, N.

May 6, 2025 8-K

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) May 6, 2025 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identification No.

May 6, 2025 EX-95

Mine Safety Disclosures

KNIFE RIVER CORPORATION MINE SAFETY INFORMATION The Dodd-Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) requires issuers to include in periodic reports filed with the SEC certain information relating to citations or orders for violations of standards under the Federal Mine Safety and Health Act of 1977 (Mine Act), as amended by the Mine Improvement and New Emergency Response Act of 2006 (Mine Safety Act).

May 6, 2025 EX-10.4

Knife River Corporation, 401(k) Retirement Plan, as amended

THIRD AMENDMENT TO KNIFE RIVER CORPORATION 401(k) RETIREMENT PLAN The Knife River Corporation 401(k) Retirement Plan (the “Plan”), as established effective May 1, 2023, is amended by this Third Amendment effective as of January 1, 2025, except as specified below.

May 6, 2025 EX-10.5

Knife River Corporation Section 16 Officers and Directors with Indemnification Agreements Chart, as of

Knife River Corporation Section 16 Officers and Directors with Indemnification Agreements As of April 19, 2025 Section 16 Officers Name Title Date of Agreement Brian R.

May 6, 2025 EX-10.3

Form of Performance Stock Unit Award Agreement under the Long-Term Performance-Based Incentive Plan, effective February 27, 2025

KNIFE RIVER CORPORATION LONG-TERM PERFORMANCE-BASED INCENTIVE PLAN PERFORMANCE STOCK UNIT AWARD AGREEMENT XXXXXX {Participant Name} In accordance with the terms of the Knife River Corporation Long-Term Performance-Based Incentive Plan (the "Plan"), pursuant to action of the Compensation Committee of the Board of Directors of Knife River Corporation (the "Committee"), Knife River Corporation (the "

May 6, 2025 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 ☐ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 1-41642 Knife River Corporation

May 6, 2025 EX-10.6

Form of Knife River Corporation Director and/or Executive Officer Indemnification Agreement

INDEMNIFICATION AGREEMENT This Indemnification Agreement (this “Agreement”) dated April 19, 2025, by and between Knife River Corporation, a Delaware corporation (the “Company”), and Sarah L.

May 6, 2025 EX-10.2

Restricted Stock Unit Award Agreement under the Long-Term Performance-Based Incentive Plan,

KNIFE RIVER CORPORATION RESTRICTED STOCK UNIT AWARD NOTICE This Award Notice evidences the award of restricted stock units (each, an “RSU” or collectively, the “RSUs”) that have been granted to, (Participant Name), by Knife River Corporation, a Delaware corporation (the “Company”), subject to your acceptance of the terms of this Award Notice, the Restricted Stock Unit Award Agreement, which is attached hereto (the “Agreement”) and the Knife River Corporation Long-Term Performance-Based Incentive Plan (the “Plan”).

April 7, 2025 DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ý Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

April 7, 2025 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ý Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

March 28, 2025 PRE 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ý Filed by a party other than the Registrant ¨ Check the appropriate box: ý Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

March 28, 2025 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) March 28, 2025 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identification

March 28, 2025 EX-99

1

Exhibit 99.1 For the year ended December 31, 2024 West Mountain Central Energy Services Total (In thousands) Revenues from external customers $ 1,182,959 $ 662,892 $ 817,872 $ 234,652 $ 2,898,375 Intersegment revenues 197,074 135,947 213,672 54,872 601,565 Total segment revenue 1,380,033 798,839 1,031,544 289,524 3,499,940 Other revenues1 16,104 Less: Elimination of intersegment revenue 617,039 To

March 10, 2025 EX-10.1

borrower, the guarantors party thereto, the lenders and other parties party thereto,

Exhibit 10.1 FIRST AMENDMENT This FIRST AMENDMENT dated as of March 7, 2025 (this “Amendment”) to the Credit Agreement (as defined below) among Knife River Corporation, a Delaware corporation (the “Borrower”), each Loan Party listed on the signature pages hereof, the Lenders and L/C Issuers party hereto and JPMORGAN CHASE BANK, N.A., as Administrative Agent. RECITALS WHEREAS, reference is made to

March 10, 2025 EX-99.1

Knife River Completes Acquisition of Strata Corporation

Exhibit 99.1 Knife River Completes Acquisition of Strata Corporation BISMARCK, N.D. — March 10, 2025 — Knife River Corporation (NYSE: KNF) announced today that it has completed its previously announced acquisition of Strata Corporation, a leading construction materials and contracting services provider in North Dakota and northwestern Minnesota. The purchase price was $454 million, reflecting a mu

March 10, 2025 8-K

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) March 7, 2025 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identification N

February 21, 2025 EX-19

Knife River Insider Trading Policy.

POLICY STATEMENTS Insider Trading Policy Effective Date: November 15, 2024 I.PURPOSE It is illegal for any director, officer or employee of Knife River Corporation and its subsidiaries (the “Company”) who possesses material non-public information concerning the Company to engage in transactions concerning the Company’s securities or to pass such information on to others who may be induced to engag

February 21, 2025 EX-95

Mine Safety Disclosures.

KNIFE RIVER CORPORATION MINE SAFETY INFORMATION The Dodd-Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) requires issuers to include in periodic reports filed with the SEC certain information relating to citations or orders for violations of standards under the Federal Mine Safety and Health Act of 1977 (Mine Act), as amended by the Mine Improvement and New Emergency Response Act of 2006 (Mine Safety Act).

February 21, 2025 EX-10.18

Knife River Corporation, 401(k) Retirement Plan, as amended December 18, 2024.

SECOND AMENDMENT TO KNIFE RIVER CORPORATION 401(k) RETIREMENT PLAN The Knife River Corporation 401(k) Retirement Plan (the “Plan”), as established effective May 1, 2023, is amended by this Second Amendment effective as of January 1, 2024, except as specified below.

February 21, 2025 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 1-41642 Knife River Corporation (Exa

February 21, 2025 EX-21

List of Subsidiaries of Knife River Corporation.

Knife River Corporation List of Subsidiaries (effective December 31, 2024) Subsidiaries Jurisdiction of Formation Alaska Basic Industries, Inc.

February 13, 2025 8-K

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) February 13, 2025 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identificati

February 13, 2025 EX-99

KNIFE RIVER CORPORATION REPORTS FOURTH QUARTER AND FULL-YEAR 2024 FINANCIAL RESULTS Achieved record full-year revenue, net income and adjusted EBITDA Continued margin expansion toward long-term goal Acquisition of Strata Corporation remains on track

KNIFE RIVER CORPORATION REPORTS FOURTH QUARTER AND FULL-YEAR 2024 FINANCIAL RESULTS Achieved record full-year revenue, net income and adjusted EBITDA Continued margin expansion toward long-term goal Acquisition of Strata Corporation remains on track Introduced full-year 2025 guidance BISMARCK, N.

January 17, 2025 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) January 17, 2025 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identificatio

December 26, 2024 8-K

Entry into a Material Definitive Agreement, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) December 20, 2024 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identificati

December 26, 2024 EX-2.1

Asset and Equity Purchase Agreement, dated December 20, 2024, by and among Strata Corporation, Glacier Resources, Ltd., the equity holders of Strata Corporation and Glacier Resources Ltd., Landmark Investments, L.L.C., the current equity holders of Landmark Investments, L.L.C., the beneficiaries of certain trusts, the sellers' representative, and KRC Holdings, Inc.

Exhibit 2.1 CERTAIN INFORMATION IDENTIFIED WITH THE MARK “[***]”, “[***%***]” AND “[***$***]” HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE SUCH INFORMATION IS BOTH (I) NOT MATERIAL AND (II) IS THE TYPE THAT THE COMPANY TREATS AS PRIVATE OR CONFIDENTIAL. ASSET AND EQUITY PURCHASE AGREEMENT by and among STRATA CORPORATION, GLACIER RESOURCES, LTD., LANDMARK INVESTMENTS, L.L.C., THE EQUITY SELLERS, THE

November 4, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 ☐ TRANSITION REPORT PURSUANT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 1-41642 Knife River Corpora

November 4, 2024 EX-95

Mine Safety Disclosures

KNIFE RIVER CORPORATION MINE SAFETY INFORMATION The Dodd-Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) requires issuers to include in periodic reports filed with the SEC certain information relating to citations or orders for violations of standards under the Federal Mine Safety and Health Act of 1977 (Mine Act), as amended by the Mine Improvement and New Emergency Response Act of 2006 (Mine Safety Act).

November 4, 2024 8-K

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) November 4, 2024 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identificatio

November 4, 2024 EX-99

KNIFE RIVER CORPORATION REPORTS THIRD QUARTER FINANCIAL RESULTS Achieved record third quarter revenue, gross profit and net income Announced recent acquisition of aggregates and liquid asphalt businesses Narrowed guidance range on revenue and adjuste

KNIFE RIVER CORPORATION REPORTS THIRD QUARTER FINANCIAL RESULTS Achieved record third quarter revenue, gross profit and net income Announced recent acquisition of aggregates and liquid asphalt businesses Narrowed guidance range on revenue and adjusted EBITDA BISMARCK, N.

November 4, 2024 EX-31.B

Certification of Chief Financial Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Nathan W. Ring, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the pe

November 4, 2024 EX-31.A

Certification of Chief Executive Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Brian R. Gray, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the per

August 21, 2024 EX-10.1

Change in Control Severance Plan

KNIFE RIVER CORPORATION CHANGE IN CONTROL SEVERANCE PLAN SECTION 1 PURPOSE OF THE PLAN The Committee (as defined in Section 2) recognizes that the possibility of a Change in Control (as defined in Section 2) of the Company (as defined in Section 2), and the uncertainty it could create, may result in the loss or distraction of employees of the Company to the detriment of the Company and its shareholders.

August 21, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) August 20, 2024 Knife River Corpo

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) August 20, 2024 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identification

August 6, 2024 8-K

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) August 6, 2024 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identification

August 6, 2024 EX-31.B

Certification of Chief Financial Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Nathan W. Ring, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the pe

August 6, 2024 EX-95

Mine Safety Disclosures

KNIFE RIVER CORPORATION MINE SAFETY INFORMATION The Dodd-Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) requires issuers to include in periodic reports filed with the SEC certain information relating to citations or orders for violations of standards under the Federal Mine Safety and Health Act of 1977 (Mine Act), as amended by the Mine Improvement and New Emergency Response Act of 2006 (Mine Safety Act).

August 6, 2024 EX-99

KNIFE RIVER CORPORATION REPORTS SECOND QUARTER FINANCIAL RESULTS Achieved record second quarter revenue, net income and adjusted EBITDA Continued to improve margins toward long-term goals Raised guidance on revenue and adjusted EBITDA

KNIFE RIVER CORPORATION REPORTS SECOND QUARTER FINANCIAL RESULTS Achieved record second quarter revenue, net income and adjusted EBITDA Continued to improve margins toward long-term goals Raised guidance on revenue and adjusted EBITDA BISMARCK, N.

August 6, 2024 EX-10.C

Knife River Corporation Section 16 Officers and Directors with Indemnification Agreements Chart, as of June 30, 2024

Knife River Corporation Section 16 Officers and Directors with Indemnification Agreements As of June 30, 2024 Section 16 Officers Name Title Date of Agreement Nancy K.

August 6, 2024 EX-10.B

Form of Knife River Corporation Restricted Stock Unit Award Agreement for Non-Employee Directors under the Long-Term Performance-Based Incentive Plan, as of May 15, 2024.

KNIFE RIVER CORPORATION RESTRICTED STOCK UNIT AWARD NOTICE (For Non-Employee Directors) This Award Notice evidences the award of restricted stock units (each, an “RSU” or collectively, the “RSUs”) that have been granted to, (XXXXXXXXX), by Knife River Corporation, a Delaware corporation (the “Company”), subject to your acceptance of the terms of this Award Notice, the Restricted Stock Unit Award Agreement, which is attached hereto (the “Agreement”) and the Knife River Corporation Long-Term Performance-Based Incentive Plan (the “Plan”).

August 6, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 ☐ TRANSITION REPORT PURSUANT TO S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 1-41642 Knife River Corporation

August 6, 2024 EX-31.A

Certification of Chief Executive Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Brian R. Gray, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the per

August 6, 2024 EX-10.A

Knife River Corporation Director Compensation Policy

KNIFE RIVER CORPORATION DIRECTOR COMPENSATION POLICY This Director Compensation Policy (the “Policy”) was adopted by the Board of Directors (the “Board”) of Knife River Corporation (the “Company”) on May 15, 2024.

June 27, 2024 8-K

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) June 27, 2024 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identification N

June 27, 2024 EX-99.1

Patricia Chiodo Appointed to Knife River Corporation Board of Directors

Patricia Chiodo Appointed to Knife River Corporation Board of Directors BISMARCK, N.

June 11, 2024 11-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 11-K ý ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 o TRANSITION REPORT PURSUANT TO SECTION 15(

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 11-K ý ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR o TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 1-41642 KNIFE RIVER CORPORATION 401(k) RETIREMEN

May 17, 2024 8-K

Financial Statements and Exhibits, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) May 14, 2024 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identification No

May 7, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 ☐ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 1-41642 Knife River Corporation

May 7, 2024 EX-99

KNIFE RIVER CORPORATION REPORTS FIRST QUARTER FINANCIAL RESULTS Achieved record first quarter revenue Increased backlog at higher expected margins Advanced organic and acquisition growth initiatives

KNIFE RIVER CORPORATION REPORTS FIRST QUARTER FINANCIAL RESULTS Achieved record first quarter revenue Increased backlog at higher expected margins Advanced organic and acquisition growth initiatives BISMARCK, N.

May 7, 2024 EX-31.B

Certification of Chief Financial Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Nathan W. Ring, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the pe

May 7, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) May 7, 2024 Knife River Corporati

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) May 7, 2024 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identification No.

May 7, 2024 EX-95

Mine Safety Disclosures

KNIFE RIVER CORPORATION MINE SAFETY INFORMATION The Dodd-Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) requires issuers to include in periodic reports filed with the SEC certain information relating to citations or orders for violations of standards under the Federal Mine Safety and Health Act of 1977 (Mine Act), as amended by the Mine Improvement and New Emergency Response Act of 2006 (Mine Safety Act).

May 7, 2024 EX-31.A

Certification of Chief Executive Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Brian R. Gray, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the per

March 29, 2024 DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ý Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

March 29, 2024 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ý Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

February 27, 2024 EX-10.8

Form of Performance Share Award Agreement under the Long-Term Performance-Based Incentive Plan, as amended February 22, 2024.

KNIFE RIVER CORPORATION LONG-TERM PERFORMANCE-BASED INCENTIVE PLAN PERFORMANCE SHARE AWARD AGREEMENT XXXXXX {Participant Name} In accordance with the terms of the Knife River Corporation Long-Term Performance-Based Incentive Plan (the "Plan"), pursuant to action of the Compensation Committee of the Board of Directors of Knife River Corporation (the "Committee"), Knife River Corporation (the "Company") hereby grants to you (the "Participant") Performance Shares (the "Award"), subject to the terms and conditions set forth in this Award Agreement (including Annexes A and B hereto and all documents incorporated herein by reference), as set forth below: Target Award: {No.

February 27, 2024 EX-21

List of Subsidiaries of Knife River Corporation.

Knife River Corporation List of Subsidiaries (effective December 31, 2023) Subsidiaries Jurisdiction of Formation Alaska Basic Industries, Inc.

February 27, 2024 EX-95

Mine Safety Disclosures

KNIFE RIVER CORPORATION MINE SAFETY INFORMATION The Dodd-Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) requires issuers to include in periodic reports filed with the SEC certain information relating to citations or orders for violations of standards under the Federal Mine Safety and Health Act of 1977 (Mine Act), as amended by the Mine Improvement and New Emergency Response Act of 2006 (Mine Safety Act).

February 27, 2024 EX-4.3

Knife River Corporation Description of Securities Registered Pursuant to Section 12 of the Securities and Exchange Act of 1934.

Exhibit 4.3 DESCRIPTION OF SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 Knife River Corporation (“we,” “our,” or “us”) has one class of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”): our common stock, par value $0.01 per share. DESCRIPTION OF CAPITAL STOCK General The following description of Kn

February 27, 2024 EX-10.7

Form of Restricted Stock Unit Award Agreement under the Long-Term Performance-Based Incentive Plan, as amended February 22, 2024.

KNIFE RIVER CORPORATION RESTRICTED STOCK UNIT AWARD NOTICE This Award Notice evidences the award of restricted stock units (each, an “RSU” or collectively, the “RSUs”) that have been granted to, (XXXXXXXXXXX), by Knife River Corporation, a Delaware corporation (the “Company”), subject to your acceptance of the terms of this Award Notice, the Restricted Stock Unit Award Agreement, which is attached hereto (the “Agreement”) and the Knife River Corporation Long-Term Performance-Based Incentive Plan (the “Plan”).

February 27, 2024 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 ☐ TRANSITION REPORT PURSUANT TO SECTI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 1-41642 Knife River Corporation (Exa

February 27, 2024 EX-97

Knife River Corporation Incentive Compensation Recovery Policy.

Incentive Compensation Recovery Policy 1.Purpose The purpose of the Knife River Corporation Incentive Compensation Recovery Policy (this “Policy”) is to provide for the recovery of certain Incentive-Based Compensation in the event of an Accounting Restatement. This Policy is intended to comply with, and to be administered and interpreted consistent with, Section 10D of the Securities Exchange Act

February 27, 2024 EX-10.16

Knife River Corporation, 401(k) Retirement Plan,

FIRST AMENDMENT TO KNIFE RIVER CORPORATION 401(k) RETIREMENT PLAN The Knife River Corporation 401(k) Retirement Plan (the “Plan”), as established effective May 1, 2023, is amended by this First Amendment effective as of January 1, 2024, except as specified below.

February 15, 2024 8-K

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) February 15, 2024 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identificati

February 15, 2024 EX-99

KNIFE RIVER CORPORATION ANNOUNCES FOURTH QUARTER AND FULL-YEAR 2023 RESULTS Reports full-year records for revenue, net income and Adjusted EBITDA Generated significant margin expansion, achieving 2025 target two years early Introduces full-year 2024

KNIFE RIVER CORPORATION ANNOUNCES FOURTH QUARTER AND FULL-YEAR 2023 RESULTS Reports full-year records for revenue, net income and Adjusted EBITDA Generated significant margin expansion, achieving 2025 target two years early Introduces full-year 2024 revenue and Adjusted EBITDA guidance BISMARCK, N.

February 13, 2024 SC 13G/A

KNF / Knife River Corporation / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 1)* Name of issuer: Knife River Corp Title of Class of Securities: Common Stock CUSIP Number: 498894104 Date of Event Which Requires Filing of this Statement: December 29, 2023 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ Ru

December 8, 2023 SC 13G

KNF / Knife River Corp / VANGUARD GROUP INC - SCHEDULE 13G Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 Name of issuer: Knife River Corp Title of Class of Securities: Common Stock CUSIP Number: 498894104 Date of Event Which Requires Filing of this Statement: November 30, 2023 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ Rule 13d-1(b) ☐ Rule 1

November 8, 2023 424B4

5,142,383 Shares KNIFE RIVER CORPORATION Common Stock

Filed Pursuant to Rule 424(b)(4) Registration No. 333-274692 PROSPECTUS SUPPLEMENT (To Prospectus dated September 28, 2023) 5,142,383 Shares KNIFE RIVER CORPORATION Common Stock The selling stockholder identified in this prospectus supplement is offering 5,142,383 shares of common stock, $0.01 par value (the “common stock”), of Knife River Corporation (“Knife River,” “we,” “us,” our” or the “Compa

November 6, 2023 EX-99

Knife River Corporation Reports Third Quarter Earnings Achieved all-time quarterly records for revenue, net income and Adjusted EBITDA Competitive EDGE initiatives drove strong margin improvement Raised guidance for revenue and Adjusted EBITDA

Knife River Corporation Reports Third Quarter Earnings Achieved all-time quarterly records for revenue, net income and Adjusted EBITDA Competitive EDGE initiatives drove strong margin improvement Raised guidance for revenue and Adjusted EBITDA BISMARCK, N.

November 6, 2023 EX-10.A

Agreement under the Long-Term Performance

KNIFE RIVER CORPORATION RESTRICTED STOCK UNIT AWARD NOTICE This Award Notice evidences the award of restricted stock units (each, an “RSU” or collectively, the “RSUs”) that have been granted to, (xxxxxxxxxxxxxx), by Knife River Corporation, a Delaware corporation (the “Company”), subject to your acceptance of the terms of this Award Notice, the Restricted Stock Unit Award Agreement, which is attached hereto (the “Agreement”) and the Knife River Corporation Long-Term Performance-Based Incentive Plan (the “Plan”).

November 6, 2023 EX-31.A

Certification of Chief Executive Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Brian R. Gray, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the per

November 6, 2023 8-K

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) November 6, 2023 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identificatio

November 6, 2023 424B3

5,142,383 KNIFE RIVER CORPORATION Common Stock

PROSPECTUS SUPPLEMENT Filed Pursuant to Rule 424(b)(3) (To Prospectus dated September 28, 2023) Registration No.

November 6, 2023 EX-31.B

Certification of Chief Financial Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Nathan W. Ring, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the pe

November 6, 2023 424B4

Subject to Completion, dated November 6, 2023

Filed Pursuant to Rule 424(b)(4) Registration No. 333-274692 The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted. Subject to Completion, dated November 6, 2023

November 6, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 ☐ TRANSITION REPORT PURSUANT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 1-41642 Knife River Corpora

November 6, 2023 EX-95

Mine Safety Disclosures

MDU RESOURCES GROUP, INC. MINE SAFETY INFORMATION The Dodd-Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) requires issuers to include in periodic reports filed with the SEC certain information relating to citations or orders for violations of standards under the Federal Mine Safety and Health Act of 1977 (Mine Act), as amended by the Mine Improvement and New Emergency Respon

November 6, 2023 424B3

PROSPECTUS SUPPLEMENT Filed Pursuant to Rule 424(b)(3) (To Prospectus dated September 28, 2023) Registration No. 333-274692 5,142,383 Shares KNIFE RIVER CORPORATION Common Stock

PROSPECTUS SUPPLEMENT Filed Pursuant to Rule 424(b)(3) (To Prospectus dated September 28, 2023) Registration No.

September 26, 2023 S-1

As filed with the Securities and Exchange Commission on September 26, 2023.

As filed with the Securities and Exchange Commission on September 26, 2023. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Knife River Corporation (Exact name of Registrant as specified in its charter) Delaware 1400 92-1008893 (State or other Jurisdiction of Incorporation or Organization

September 26, 2023 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Knife River Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit(1) Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Fees to Be Paid Equity Common stock, par value $0.

September 1, 2023 DRS

FOIA Confidential Treatment Requested by Knife River Corporation Pursuant to 17 C.F.R. 200.83 As confidentially submitted to the Securities and Exchange Commission on September 1, 2023. This draft registration statement has not been publicly filed wi

FOIA Confidential Treatment Requested by Knife River Corporation Pursuant to 17 C.

August 8, 2023 EX-95

Mine Safety Disclosures

MDU RESOURCES GROUP, INC. MINE SAFETY INFORMATION The Dodd-Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) requires issuers to include in periodic reports filed with the SEC certain information relating to citations or orders for violations of standards under the Federal Mine Safety and Health Act of 1977 (Mine Act), as amended by the Mine Improvement and New Emergency Respon

August 8, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) August 8, 2023 Knife River Corpor

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) August 8, 2023 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of (Commission File Number) (I.R.S. Employer Identification

August 8, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 ☐ TRANSITION REPORT PURSUANT TO S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 1-41642 Knife River Corporation

August 8, 2023 EX-31.A

Certification of Chief Executive Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Brian R. Gray, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the per

August 8, 2023 EX-99

Knife River Corporation Reports Second Quarter Earnings Achieved record second quarter revenue, net income, EBITDA and backlog Reduced net debt leverage to 2.3x EBITDA Raised revenue and EBITDA guidance; initiated adjusted EBITDA guidance

Knife River Corporation Reports Second Quarter Earnings Achieved record second quarter revenue, net income, EBITDA and backlog Reduced net debt leverage to 2.

August 8, 2023 EX-31.B

Certification of Chief Financial Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Nathan W. Ring, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the pe

August 8, 2023 EX-10.L

Knife River Corporation, 401(k) Retirement Plan, effective May 1, 2023.

KNIFE RIVER CORPORATION 401(K) RETIREMENT PLAN Effective May 1, 2023 161329235.2 TABLE OF CONTENTS Page INTRODUCTION 1 ARTICLE I DEFINITIONS 2 ARTICLE II PARTICIPATION 9 2.1 Participation Requirements 9 2.2 Termination of Participation 9 2.3 Reemployment 10 ARTICLE III CONTRIBUTIONS 11 3.1 Deferral Contributions 11 3.2 Changing Deferral Contribution Election 12 3.3 In-Plan Roth Conversion 12 3.4 M

June 2, 2023 EX-FILING FEES

Calculation of Filing Fee Tables Form S-8 (Form Type) Knife River Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities

Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) Knife River Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Newly Registered Securities Fees to Be Paid Equity Common Stock, $1.

June 2, 2023 S-8

As filed with the Securities and Exchange Commission on June 2, 2023

As filed with the Securities and Exchange Commission on June 2, 2023 Registration No.

June 2, 2023 EX-FILING FEES

Calculation of Filing Fee Tables Form S-8 (Form Type) Knife River Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities

Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) Knife River Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Newly Registered Securities Fees to Be Paid Equity Common Stock, $1.

June 2, 2023 S-8

As filed with the Securities and Exchange Commission on June 2, 2023

As filed with the Securities and Exchange Commission on June 2, 2023 Registration No.

June 1, 2023 EX-10.8

Knife River Corporation Supplemental Income Security Plan.

Exhibit 10.8 KNIFE RIVER CORPORATION SUPPLEMENTAL INCOME SECURITY PLAN TABLE OF CONTENTS Page INTRODUCTION 1 Article I - DEFINITIONS 2 Article II - ELIGIBILITY 5 Article III - SUPPLEMENTAL DEATH AND RETIREMENT BENEFITS 7 Article IV – [RESERVED.] 17 Article V - DISABILITY BENEFITS 17 Article VI - MISCELLANEOUS 17 Article VII - ADDITIONAL AFFILIATED COMPANIES 26 APPENDIX A AND A-1 SCHEDULE OF RETIRE

June 1, 2023 EX-3.1

Amended and Restated Certificate of Incorporation of Knife River Corporation

Exhibit 3.1 AMENDED and restated CERTIFICATE OF INCORPORATION OF KNIFE RIVER HOLDING COMPANY Knife River Holding Company (the “Corporation”), a corporation organized and existing under the laws of the State of Delaware, pursuant to Sections 242 and 245 of the General Corporation Law of the State of Delaware, as it may be amended (the “DGCL”), hereby certifies as follows: 1. The name of this Corpor

June 1, 2023 EX-10.7

Knife River Corporation Deferred Compensation Plan-Plan Document and Adoption Agreement.

Exhibit 10.7 KNIFE RIVER CORPORATION DEFERRED COMPENSATION PLAN PLAN DOCUMENT THE KNIFE RIVER CORPORATION DEFERRED COMPENSATION PLAN Section 1. Purpose By execution of the Adoption Agreement, the Company has adopted the Plan set forth herein, and in the Adoption Agreement, to provide a means by which certain management Employees or Independent Contractors of the Employer may elect to defer receipt

June 1, 2023 EX-10.10

Knife River Corporation Director Compensation Policy.

Exhibit 10.10 KNIFE RIVER CORPORATION DIRECTOR COMPENSATION POLICY This Director Compensation Policy (the “Policy”) was adopted by the Board of Directors (the “Board”) of Knife River Corporation formerly known as Knife River Holding Company (the “Company”) in connection with the distribution of 80.1% or more of the outstanding shares of the Company’s common stock to the stockholders of MDU Resourc

June 1, 2023 EX-10.2

Tax Matters Agreement, dated as of May 30, 2023, by and between Knife River Corporation and MDU Resources Group, Inc.

Exhibit 10.2 TAX MATTERS AGREEMENT DATED AS OF MAY 30, 2023 BY AND BETWEEN MDU RESOURCES GROUP, INC. AND KNIFE RIVER HOLDING COMPANY TABLE OF CONTENTS Page Section 1. Definition of Terms 2 Section 2. Allocation of Tax Liabilities 12 Section 2.01 General Rule 12 Section 2.02 Allocation of United States Federal Income Tax and Federal Other Tax 13 Section 2.03 Allocation of State Income Tax and State

June 1, 2023 EX-4.2

Supplemental Indenture, dated as of May 31, 2023, by and among the parties that are signatories thereto as Guarantors, Knife River Corporation and U.S. Bank Trust Company, National Association

Exhibit 4.2 Supplemental Indenture SUPPLEMENTAL INDENTURE, dated as of May 31, 2023 (this “Supplemental Indenture”), by and among the parties that are signatories hereto as Guarantors (each, a “Guaranteeing Subsidiary” and together, the “Guaranteeing Subsidiaries”), Knife River Holding Company (to be renamed Knife River Corporation on the Spin-Off Date), a Delaware Corporation (the “Issuer”), and

June 1, 2023 EX-4.1

Stockholder and Registration Rights Agreement, dated as of May 30, 2023, by and between Knife River Corporation and MDU Resources Group, Inc.

Exhibit 4.1 STOCKHOLDER AND REGISTRATION RIGHTS AGREEMENT BY AND BETWEEN MDU RESOURCES GROUP, INC. AND KNIFE RIVER HOLDING COMPANY DATED AS OF MAY 30, 2023 TABLE OF CONTENTS Page TABLE OF CONTENTS i ARTICLE I DEFINITIONS 1 ARTICLE II REGISTRATION RIGHTS 6 Section 2.01 Registration 6 Section 2.02 Piggyback Registrations 10 Section 2.03 Registration Procedures 12 Section 2.04 Underwritten Offerings

June 1, 2023 EX-10.4

Credit Agreement, dated as of May 31, 2023, by and among Knife River Corporation, JPMorgan Chase Bank, N.A. and Lenders and L/C Issuers party thereto.

Exhibit 10.4 CREDIT AGREEMENT DATED AS OF MAY 31, 2023 AMONG KNIFE RIVER HOLDING COMPANY, AS THE BORROWER, JPMORGAN CHASE BANK, N.A., AS ADMINISTRATIVE AGENT AND COLLATERAL AGENT AND THE LENDERS AND L/C ISSUERS PARTY HERETO JPMORGAN CHASE BANK, N.A., BOFA SECURITIES, INC., MUFG BANK, LTD., RBC CAPITAL MARKETS1, U.S. BANK NATIONAL ASSOCIATION AND WELLS FARGO SECURITIES, LLC, AS JOINT LEAD ARRANGERS

June 1, 2023 EX-10.6

Knife River Corporation Executive Incentive Compensation Plan, including Rules and Regulations.

Exhibit 10.6 KNIFE RIVER CORPORATION EXECUTIVE INCENTIVE COMPENSATION PLAN I. ESTABLISHMENT AND PURPOSE The Executive Incentive Compensation Plan (the “Plan”) was adopted by the Board of Directors of Knife River Corporation (formerly known as Knife River Holding Company) (“KRC”) in connection with the distribution of 80.1% or more of the outstanding shares of KRC’s common stock to the stockholders

June 1, 2023 EX-10.3

Employee Matters Agreement, dated as of May 30, 2023, by and between Knife River Corporation and MDU Resources Group, Inc.

Exhibit 10.3 EMPLOYEE MATTERS AGREEMENT BY AND BETWEEN MDU RESOURCES GROUP, INC. AND KNIFE RIVER HOLDING COMPANY DATED AS OF May 30, 2023 TABLE OF CONTENTS Page Article I DEFINITIONS Section 1.01 Definitions 1 Section 1.02 Interpretation 7 Article II GENERAL PRINCIPLES FOR ALLOCATION OF LIABILITIES Section 2.01 General Principles 7 Section 2.02 Service Credit Recognized by SpinCo and SpinCo Benefi

June 1, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 30, 2023 Knife River Corpora

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 30, 2023 Knife River Corporation (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation) (Commission File Number) (I.R.S. Employer I

June 1, 2023 EX-10.1

Transition Services Agreement, dated as of May 30, 2023, by and between Knife River Corporation and MDU Resources Group, Inc.

Exhibit 10.1 TRANSITION SERVICES AGREEMENT by and between MDU Resources Group, Inc. and Knife river holding company dated as of May 30, 2023 TABLE OF CONTENTS Page ARTICLE I DEFINITIONS 2 Section 1.01. Definitions 2 ARTICLE II SERVICES 7 Section 2.01. Services 7 Section 2.02. Performance of Services 7 Section 2.03. Charges for Services 8 Section 2.04. Reimbursement for Out-of-Pocket Costs and Expe

June 1, 2023 EX-2.1

Separation and Distribution Agreement, dated as of May 30, 2023, by and between Knife River Corporation and MDU Resources Group, Inc.

Exhibit 2.1 SEPARATION AND DISTRIBUTION AGREEMENT BY AND BETWEEN MDU RESOURCES GROUP, INC. AND KNIFE RIVER HOLDING COMPANY DATED AS OF MAY 30, 2023 TABLE OF CONTENTS Page ARTICLE I DEFINITIONS 2 1.1 Definitions 2 ARTICLE II THE SEPARATION 14 2.1 Transfer of Assets and Assumption of Liabilities 14 2.2 SpinCo Assets; Parent Assets 16 2.3 SpinCo Liabilities; Parent Liabilities 18 2.4 Approvals and No

June 1, 2023 EX-10.11

Knife River Corporation Deferred Compensation Plan for Directors.

Exhibit 10.11 KNIFE RIVER CORPORATION DEFERRED COMPENSATION PLAN FOR DIRECTORS I. PURPOSE The Board of Directors of Knife River Corporation (the “Company”) established this Deferred Compensation Plan for Directors (the “Plan”) in connection with the distribution of 80.1% or more of the outstanding shares of the Company’s common stock to the stockholders of MDU Resources Group, Inc. (“MDU”) in 2023

June 1, 2023 EX-10.9

Knife River Corporation Nonqualified Defined Contribution Plan.

Exhibit 10.9 Knife river corporation NONQUALIFIED DEFINED CONTRIBUTION PLAN WHEREAS, the Board of Directors of Knife River Corporation (formerly known as Knife River Holding Company) (the “Company”) established this Knife River Corporation Nonqualified Defined Contribution Plan (the “Plan”) in connection with the distribution of 80.1% or more of the outstanding shares of the Company’s common stock

June 1, 2023 EX-99.2

Knife River Corporation Completes Spinoff from MDU Resources

Exhibit 99.2 NEWS RELEASE 1150 W. Century Ave. Bismarck, ND 58503 Knife River Corporation Completes Spinoff from MDU Resources BISMARCK, N.D. — June 1, 2023 — Knife River Corporation (NYSE: KNF) today announced the successful completion of its spinoff from MDU Resources Group, Inc. (NYSE: MDU). As a result of the spinoff, Knife River is now an independent, public company that will begin “regular w

June 1, 2023 EX-3.2

Amended and Restated Bylaws of Knife River Corporation

Exhibit 3.2 AMENDED AND RESTATED BYLAWS OF KNIFE RIVER CORPORATION These Amended and Restated Bylaws (these “Bylaws”) of Knife River Corporation, a Delaware corporation (the “Corporation”), are effective as of June 1, 2023 and hereby amend and restate the previous bylaws of the Corporation in its entirety: Article 1 OFFICES AND RECORDS Section 1. Offices. The address of the registered office of th

June 1, 2023 EX-10.5

Knife River Corporation Long Term Performance-Based Incentive Plan.

Exhibit 10.5 KNIFE RIVER CORPORATION LONG-TERM PERFORMANCE-BASED INCENTIVE PLAN Article 1 Establishment, Purpose and Duration 1.1 Purpose of the Plan. The purpose of the Knife River Corporation Long-Term Performance-Based Incentive Plan (hereinafter referred to as the “Plan”) is to promote the success and enhance the value of the Company by linking the personal interests of Participants to those o

May 18, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 18, 2023 Knife River Holding

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 18, 2023 Knife River Holding Company (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation) (Commission File Number) (I.R.S. Employ

May 18, 2023 EX-99.1

Forward 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, s

Exhibit 99.1 Forward 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. I

May 16, 2023 EX-31.A

Certification of Chief Executive Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Brian R. Gray, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Holding Company; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the

May 16, 2023 EX-10.5

Promotion Letter with Glenn R. Pladsen dated as of March 15, 2023

Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc.

May 16, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 ☐ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 1-41642 Knife River Holding Com

May 16, 2023 EX-10.4

Promotion Letter with Marney L. Kadrmas dated as of March 15, 2023

Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc.

May 16, 2023 EX-3.A

Certificate of Incorporation of Knife River Holding Company

CERTIFICATE OF INCORPORATION OF KNIFE RIVER HOLDING COMPANY I, the undersigned, for the purpose of incorporating and organizing a corporation under the General Corporation Law of the State of Delaware, do hereby execute this Certificate of Incorporation and do hereby certify as follows: ARTICLE I The name of the corporation (which is hereinafter referred to as the “Corporation”) is: Knife River Holding Company ARTICLE II The registered office of the Corporation in the State of Delaware is located at 1209 Orange Street, Wilmington, New Castle County, Delaware 19801.

May 16, 2023 EX-10.2

Promotion Letter with John F. Quade dated as of January 31, 2023

Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc.

May 16, 2023 EX-10.9

Promotion Letter with Brian R. Gray dated as of March 27, 2023

Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc.

May 16, 2023 EX-10.6

Promotion Letter with Nancy K. Christenson dated as of March 15, 2023

Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc.

May 16, 2023 EX-10.3

Promotion Letter with Nathan W. Ring dated as of March 15, 2023

Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc.

May 16, 2023 EX-3.C

Certificate of Amendment of the Certificate of Incorporation of Knife River Holding Company

KNIFE RIVER HOLDING COMPANY CERTIFICATE OF AMENDMENT OF THE CERTIFICATE OF INCORPORATION Knife River Holding Company (the “Company”), a corporation organized and existing under and by virtue of the General Corporation Law of the State of Delaware (the “DGCL”) DOES HEREBY CERTIFY: FIRST: That the original certificate of incorporation of the Company was filed with the Secretary of the State of Delaware on November 9, 2022.

May 16, 2023 EX-95

Mine Safety Disclosures

MDU RESOURCES GROUP, INC. MINE SAFETY INFORMATION The Dodd-Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) requires issuers to include in periodic reports filed with the SEC certain information relating to citations or orders for violations of standards under the Federal Mine Safety and Health Act of 1977 (Mine Act), as amended by the Mine Improvement and New Emergency Respon

May 16, 2023 EX-10.8

Promotion Letter with Trevor J. Hastings dated as of March 15, 2023

Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc.

May 16, 2023 EX-10.7

Promotion Letter with Karl A. Liepitz dated as of March 15, 2023

Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc.

May 16, 2023 EX-31.B

Certification of Chief Financial Officer filed pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

CERTIFICATION I, Nathan W. Ring, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Knife River Holding Company; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to th

May 16, 2023 EX-3.B

Bylaws of Knife River Holding Company

BY-LAWS of KNIFE RIVER HOLDING COMPANY dated as of November 9, 2022 TABLE OF CONTENTS Page ARTICLE I OFFICES SECTION 1.

May 12, 2023 EX-99.1

INFORMATION STATEMENT Knife River Holding Company Common Stock (par value $0.01 per share)

TABLE OF CONTENTS Exhibit 99.1   May 12, 2023 Dear MDU Resources Group, Inc. Stockholder: On August 4, 2022, we announced plans to separate our wholly owned subsidiary Knife River Corporation (“Knife River” or the “Company”) from MDU Resources Group, Inc. (“MDU Resources”). The separation will occur by means of a spinoff, intended to be tax-free, of a newly formed company named Knife River Holding

May 12, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 10, 2023 Knife River Holding Company (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation) (Commission File Number) (I.R.S. Employ

May 8, 2023 10-12B/A

As filed with the Securities and Exchange Commission on May 8, 2023.

As filed with the Securities and Exchange Commission on May 8, 2023. File No. 001-41642 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Amendment No. 3   to   FORM 10 GENERAL FORM FOR REGISTRATION OF SECURITIES Pursuant to Section 12(b) or (g) of the Securities Exchange Act of 1934 Knife River Holding Company* (Exact name of Registrant as specified in its charter) Delaware

May 8, 2023 CORRESP

Knife River Holding Company 1150 West Century Avenue Bismarck, ND 58503

Knife River Holding Company 1150 West Century Avenue Bismarck, ND 58503 May 8, 2023 VIA EDGAR SUBMISSION Office of Energy & Transportation Division of Corporation Finance U.

May 8, 2023 EX-99.1

Exhibit 99.1

TABLE OF CONTENTS Exhibit 99.1   May [  ], 2023 Dear MDU Resources Group, Inc. Stockholder: On August 4, 2022, we announced plans to separate our wholly owned subsidiary Knife River Corporation (“Knife River” or the “Company”) from MDU Resources Group, Inc. (“MDU Resources”). The separation will occur by means of a spinoff, intended to be tax-free, of a newly formed company named Knife River Holdi

May 3, 2023 CORRESP

[Letterhead of Wachtell, Lipton, Rosen & Katz]

[Letterhead of Wachtell, Lipton, Rosen & Katz] May 3, 2023 VIA EDGAR SUBMISSION Office of Energy & Transportation Division of Corporation Finance U.

April 28, 2023 EX-10.10

Promotion Letter with Marney Kadrmas dated as of March 15, 2023.

Exhibit 10.10 www.kniferiver.com PO Box 5568 Bismarck, ND 58506-5568 Street Address: 1150 West Century Avenue Bismarck, ND 58506 (701) 530-1400 (701) 530-1451 Fax Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc. (“MDU Resources”). As you

April 28, 2023 EX-99.1

Information contained herein is subject to completion or amendment. A Registration Statement on Form 10 relating to these securities has been filed with the U.S. Securities and Exchange Commission under the U.S. Securities Exchange Act of 1934, as am

TABLE OF CONTENTS Exhibit 99.1   [   ], 2023 Dear MDU Resources Group, Inc. Stockholder: On August 4, 2022, we announced plans to separate our wholly owned subsidiary Knife River Corporation (“Knife River” or the “Company”) from MDU Resources Group, Inc. (“MDU Resources”). The separation will occur by means of a spinoff, intended to be tax-free, of a newly formed company named Knife River Holding

April 28, 2023 EX-10.6

Form of KNIFE RIVER CORPORATION SUPPLEMENTAL INCOME SECURITY PLAN TABLE OF CONTENTS

Exhibit 10.6 Form of KNIFE RIVER CORPORATION SUPPLEMENTAL INCOME SECURITY PLAN TABLE OF CONTENTS Page INTRODUCTION 1 Article I - DEFINITIONS 2 Article II - ELIGIBILITY 5 Article III - SUPPLEMENTAL DEATH AND RETIREMENT BENEFITS 7 Article IV – [RESERVED.] 17 Article V - DISABILITY BENEFITS 17 Article VI - MISCELLANEOUS 17 Article VII - ADDITIONAL AFFILIATED COMPANIES 26 APPENDIX A AND A-1 SCHEDULE O

April 28, 2023 EX-2.1

SEPARATION AND DISTRIBUTION AGREEMENT BY AND BETWEEN MDU RESOURCES GROUP, INC. KNIFE RIVER HOLDING COMPANY DATED AS OF [ ], 2023 TABLE OF CONTENTS

Exhibit 2.1 SEPARATION AND DISTRIBUTION AGREEMENT BY AND BETWEEN MDU RESOURCES GROUP, INC. AND KNIFE RIVER HOLDING COMPANY DATED AS OF [ ], 2023 TABLE OF CONTENTS Page ARTICLE I DEFINITIONS 2 1.1 Definitions 2 ARTICLE II THE SEPARATION 14 2.1 Transfer of Assets and Assumption of Liabilities 14 2.2 SpinCo Assets; Parent Assets 16 2.3 SpinCo Liabilities; Parent Liabilities 18 2.4 Approvals and Notif

April 28, 2023 EX-4.2

Indenture, dated as of April 25, 2023, by and among Knife River Corporation and U.S. Bank Trust Company, National Association

Exhibit 4.2 EXECUTION VERSION Knife River Holding Company (to be renamed Knife River Corporation on the Spin-off date), as Issuer, the Guarantors party hereto from time to time, AND U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, as Trustee 7.750% Senior Notes due 2031 INDENTURE Dated as of April 25, 2023 Table of Contents Page Article I DEFINITIONS AND INCORPORATION BY REFERENCE SECTION 1.01 Defin

April 28, 2023 EX-10.13

Promotion Letter with Karl Liepitz dated as of March 15, 2023.

Exhibit 10.13 www.kniferiver.com PO Box 5568 Bismarck, ND 58506-5568 Street Address: 1150 West Century Avenue Bismarck, ND 58506 (701) 530-1400 (701) 530-1451 Fax Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc. (“MDU Resources”). As you

April 28, 2023 EX-10.8

Promotion Letter with John Quade dated as of January 31, 2023.

Exhibit 10.8 www.kniferiver.com PO Box 5568 Bismarck, ND 58506-5568 Street Address: 1150 West Century Avenue Bismarck, ND 58506 (701) 530-1400 (701) 530-1451 Fax Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc. (“MDU Resources”). As you k

April 28, 2023 EX-10.3

FORM OF KNIFE RIVER CORPORATION DIRECTOR COMPENSATION POLICY

Exhibit 10.3 FORM OF KNIFE RIVER CORPORATION DIRECTOR COMPENSATION POLICY This Director Compensation Policy (the “Policy”) was adopted by the Board of Directors (the “Board”) of Knife River Corporation formerly known as Knife River Holding Company (the “Company”) in connection with the distribution of 80.1% or more of the outstanding shares of the Company’s common stock to the stockholders of MDU

April 28, 2023 EX-10.15

Promotion Letter with Brian R. Gray dated as of March 27, 2023.

Exhibit 10.15 www.kniferiver.com PO Box 5568 Bismarck, ND 58506-5568 Street Address: 1150 West Century Avenue Bismarck, ND 58506 (701) 530-1400 (701) 530-1451 Fax Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc. (“MDU Resources”). As you

April 28, 2023 EX-2.4

FORM OF EMPLOYEE MATTERS AGREEMENT BY AND BETWEEN MDU RESOURCES GROUP, INC. KNIFE RIVER HOLDING COMPANY DATED AS OF [ ], 2023 TABLE OF CONTENTS

Exhibit 2.4 FORM OF EMPLOYEE MATTERS AGREEMENT BY AND BETWEEN MDU RESOURCES GROUP, INC. AND KNIFE RIVER HOLDING COMPANY DATED AS OF [ ], 2023 TABLE OF CONTENTS Page Article I DEFINITIONS Section 1.01 Definitions 1 Section 1.02 Interpretation 7 Article II GENERAL PRINCIPLES FOR ALLOCATION OF LIABILITIES Section 2.01 General Principles 7 Section 2.02 Service Credit Recognized by SpinCo and SpinCo Be

April 28, 2023 EX-10.9

Promotion Letter with Nathan Ring dated as of March 15, 2023.

Exhibit 10.9 www.kniferiver.com PO Box 5568 Bismarck, ND 58506-5568 Street Address: 1150 West Century Avenue Bismarck, ND 58506 (701) 530-1400 (701) 530-1451 Fax Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc. (“MDU Resources”). As you k

April 28, 2023 EX-10.11

Promotion Letter with Glenn Pladsen dated as of March 15, 2023.

Exhibit 10.11 www.kniferiver.com PO Box 5568 Bismarck, ND 58506-5568 Street Address: 1150 West Century Avenue Bismarck, ND 58506 (701) 530-1400 (701) 530-1451 Fax Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc. (“MDU Resources”). As you

April 28, 2023 EX-10.4

form of KNIFE RIVER CORPORATION DEFERRED COMPENSATION PLAN FOR DIRECTORS

Exhibit 10.4 form of KNIFE RIVER CORPORATION DEFERRED COMPENSATION PLAN FOR DIRECTORS I. PURPOSE The Board of Directors of Knife River Corporation (the “Company”) established this Deferred Compensation Plan for Directors (the “Plan”) in connection with the distribution of 80.1% or more of the outstanding shares of the Company’s common stock to the stockholders of MDU Resources Group, Inc. (“MDU”)

April 28, 2023 EX-10.12

Promotion Letter with Nancy Christenson dated as of March 15, 2023.

Exhibit 10.12 www.kniferiver.com PO Box 5568 Bismarck, ND 58506-5568 Street Address: 1150 West Century Avenue Bismarck, ND 58506 (701) 530-1400 (701) 530-1451 Fax Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc. (“MDU Resources”). As you

April 28, 2023 EX-10.16

Form of Knife River Corporation Director and/or Executive Officer Indemnification Agreement

Exhibit 10.16 INDEMNIFICATION AGREEMENT This Indemnification Agreement (this “Agreement”) dated [ ], by and between Knife River Corporation, a Delaware corporation (the “Company”), and [ ], an individual (the “Indemnitee”). Recitals WHEREAS, it is essential to the Company to retain and attract as directors and officers the most capable persons available; WHEREAS, the Indemnitee is a director and/o

April 28, 2023 EX-2.3

TAX MATTERS AGREEMENT DATED AS OF [ ] BY AND BETWEEN MDU RESOURCES GROUP, INC. KNIFE RIVER HOLDING COMPANY TABLE OF CONTENTS

Exhibit 2.3 TAX MATTERS AGREEMENT DATED AS OF [ ] BY AND BETWEEN MDU RESOURCES GROUP, INC. AND KNIFE RIVER HOLDING COMPANY TABLE OF CONTENTS Page Section 1. Definition of Terms 2 Section 2. Allocation of Tax Liabilities 12 Section 2.01 General Rule 12 Section 2.02 Allocation of United States Federal Income Tax and Federal Other Tax 13 Section 2.03 Allocation of State Income Tax and State Other Tax

April 28, 2023 CORRESP

[Letterhead of Wachtell, Lipton, Rosen & Katz] April 28, 2023

CORRESP 1 filename1.htm [Letterhead of Wachtell, Lipton, Rosen & Katz] April 28, 2023 VIA EDGAR SUBMISSION Office of Energy & Transportation Division of Corporation Finance U.S. Securities & Exchange Commission 100 F Street, NE Washington, D.C. 20549 Attention: Jennifer O’Brien Shannon Buskirk George K. Schuler Anuja Majmudar Kevin Dougherty Re: Knife River Holding Co. Amendment No. 1 to Registrat

April 28, 2023 EX-10.5

FORM OF KNIFE RIVER CORPORATION DEFERRED COMPENSATION PLAN PLAN DOCUMENT THE KNIFE RIVER CORPORATION DEFERRED COMPENSATION PLAN

Exhibit 10.5 FORM OF KNIFE RIVER CORPORATION DEFERRED COMPENSATION PLAN PLAN DOCUMENT THE KNIFE RIVER CORPORATION DEFERRED COMPENSATION PLAN Section 1. Purpose By execution of the Adoption Agreement, the Company has adopted the Plan set forth herein, and in the Adoption Agreement, to provide a means by which certain management Employees or Independent Contractors of the Employer may elect to defer

April 28, 2023 EX-10.7

form of Knife river corporation NONQUALIFIED DEFINED CONTRIBUTION PLAN

Exhibit 10.7 form of Knife river corporation NONQUALIFIED DEFINED CONTRIBUTION PLAN WHEREAS, the Board of Directors of Knife River Corporation (formerly known as Knife River Holding Company) (the “Company”) established this Knife River Corporation Nonqualified Defined Contribution Plan (the “Plan”) in connection with the distribution of 80.1% or more of the outstanding shares of the Company’s comm

April 28, 2023 EX-10.14

Promotion Letter with Trevor Hastings dated as of March 15, 2023.

Exhibit 10.14 www.kniferiver.com PO Box 5568 Bismarck, ND 58506-5568 Street Address: 1150 West Century Avenue Bismarck, ND 58506 (701) 530-1400 (701) 530-1451 Fax Re: Offer Letter As discussed, I am pleased to deliver the attached offer letter relating to your employment with Knife River Corporation (the “Employer”), a wholly owned subsidiary of MDU Resources Group, Inc. (“MDU Resources”). As you

April 28, 2023 10-12B/A

File No. 001-41642

As filed with the Securities and Exchange Commission on April 28, 2023. File No. 001-    UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Amendment No. 2   to   FORM 10 GENERAL FORM FOR REGISTRATION OF SECURITIES Pursuant to Section 12(b) or (g) of the Securities Exchange Act of 1934 Knife River Holding Company* (Exact name of Registrant as specified in its charter) Delaware

April 7, 2023 EX-2.2

TRANSITION SERVICES AGREEMENT by and between MDU Resources Group, Inc. Knife river holding company dated as of [ ], 2023 TABLE OF CONTENTS

Exhibit 2.2 TRANSITION SERVICES AGREEMENT by and between MDU Resources Group, Inc. and Knife river holding company dated as of [ ], 2023 TABLE OF CONTENTS Page ARTICLE I DEFINITIONS 2 Section 1.01. Definitions 2 ARTICLE II SERVICES 7 Section 2.01. Services 7 Section 2.02. Performance of Services 7 Section 2.03. Charges for Services 8 Section 2.04. Reimbursement for Out-of-Pocket Costs and Expenses

April 7, 2023 EX-4.1

STOCKHOLDER AND REGISTRATION RIGHTS AGREEMENT BY AND BETWEEN MDU RESOURCES GROUP, INC. KNIFE RIVER HOLDING COMPANY DATED AS OF [ ], 2023 TABLE OF CONTENTS

Exhibit 4.1 STOCKHOLDER AND REGISTRATION RIGHTS AGREEMENT BY AND BETWEEN MDU RESOURCES GROUP, INC. AND KNIFE RIVER HOLDING COMPANY DATED AS OF [ ], 2023 TABLE OF CONTENTS Page TABLE OF CONTENTS i ARTICLE I DEFINITIONS 1 ARTICLE II REGISTRATION RIGHTS 6 Section 2.01 Registration 6 Section 2.02 Piggyback Registrations 10 Section 2.03 Registration Procedures 12 Section 2.04 Underwritten Offerings or

April 7, 2023 EX-10

FORM OF KNIFE RIVER CORPORATION EXECUTIVE INCENTIVE COMPENSATION PLAN

Exhibit 10.2 FORM OF KNIFE RIVER CORPORATION EXECUTIVE INCENTIVE COMPENSATION PLAN I. ESTABLISHMENT AND PURPOSE The Executive Incentive Compensation Plan (the “Plan”) was adopted by the Board of Directors of Knife River Corporation (formerly known as Knife River Holding Company) (“KRC”) in connection with the distribution of 80.1% or more of the outstanding shares of KRC’s common stock to the stoc

April 7, 2023 EX-99.1

Information contained herein is subject to completion or amendment. A Registration Statement on Form 10 relating to these securities has been filed with the U.S. Securities and Exchange Commission under the U.S. Securities Exchange Act of 1934, as am

TABLE OF CONTENTS Exhibit 99.1   [   ], 2023 Dear MDU Resources Group, Inc. Stockholder: On August 4, 2022, we announced plans to separate our wholly owned subsidiary Knife River Corporation (“Knife River” or the “Company”) from MDU Resources Group, Inc. (“MDU Resources”). The separation will occur by means of a spinoff, intended to be tax-free, of a newly formed company named Knife River Holding

April 7, 2023 EX-3.2

FORM OF AMENDED AND RESTATED BYLAWS OF KNIFE RIVER CORPORATION

Exhibit 3.2 FORM OF AMENDED AND RESTATED BYLAWS OF KNIFE RIVER CORPORATION These Amended and Restated Bylaws (these “Bylaws”) of Knife River Corporation, a Delaware corporation (the “Corporation”), are effective as of [ ], 2023 and hereby amend and restate the previous bylaws of the Corporation in its entirety: Article 1 OFFICES AND RECORDS Section 1. Offices. The address of the registered office

April 7, 2023 EX-99.2

EX-99.2

Exhibit 99.2

April 7, 2023 CORRESP

[Letterhead of Wachtell, Lipton, Rosen & Katz] April 7, 2023

[Letterhead of Wachtell, Lipton, Rosen & Katz] April 7, 2023 VIA EDGAR SUBMISSION Office of Energy & Transportation Division of Corporation Finance U.

April 7, 2023 EX-10.1

FORM OF KNIFE RIVER CORPORATION LONG-TERM PERFORMANCE-BASED INCENTIVE PLAN Article 1 Establishment, Purpose and Duration

Exhibit 10.1 FORM OF KNIFE RIVER CORPORATION LONG-TERM PERFORMANCE-BASED INCENTIVE PLAN Article 1 Establishment, Purpose and Duration 1.1 Purpose of the Plan. The purpose of the Knife River Corporation Long-Term Performance-Based Incentive Plan (hereinafter referred to as the “Plan”) is to promote the success and enhance the value of the Company by linking the personal interests of Participants to

April 7, 2023 EX-3.1

AMENDED and restated CERTIFICATE OF INCORPORATION OF KNIFE RIVER CORPORATION

Exhibit 3.1 AMENDED and restated CERTIFICATE OF INCORPORATION OF KNIFE RIVER CORPORATION Knife River Holding Company (the “Corporation”), a corporation organized and existing under the laws of the State of Delaware, pursuant to Sections 242 and 245 of the General Corporation Law of the State of Delaware, as it may be amended (the “DGCL”), hereby certifies as follows: 1. The name of this Corporatio

April 7, 2023 10-12B/A

As filed with the Securities and Exchange Commission on April 7, 2023.

As filed with the Securities and Exchange Commission on April 7, 2023. File No. 001-    UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Amendment No. 1   to   FORM 10 GENERAL FORM FOR REGISTRATION OF SECURITIES Pursuant to Section 12(b) or (g) of the Securities Exchange Act of 1934 Knife River Holding Company (Exact name of Registrant as specified in its charter) Delaware (

March 10, 2023 CORRESP

[Letterhead of Wachtell, Lipton, Rosen & Katz] March 10, 2023

[Letterhead of Wachtell, Lipton, Rosen & Katz] March 10, 2023 VIA EDGAR SUBMISSION Office of Energy & Transportation Division of Corporation Finance U.

March 10, 2023 EX-21.1

List of Subsidiaries of Knife River Corporation.

Exhibit 21.1 SUBSIDIARIES OF KNIFE RIVER HOLDING COMPANY The following entities are expected to be subsidiaries of Knife River Holding Company upon completion of the distribution described in the information statement: Subsidiaries State of Incorporation Knife River Corporation Delaware Alaska Basic Industries, Inc. Alaska Ames Sand & Gravel, Inc. North Dakota Anchorage Sand and Gravel Company, In

March 10, 2023 10-12B

As filed with the Securities and Exchange Commission on March 10, 2023.

As filed with the Securities and Exchange Commission on March 10, 2023. File No. 001-    UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10 GENERAL FORM FOR REGISTRATION OF SECURITIES Pursuant to Section 12(b) or (g) of the Securities Exchange Act of 1934 Knife River Holding Company (Exact name of Registrant as specified in its charter) Delaware (State or Other Jurisdi

March 10, 2023 EX-99.1

Information contained herein is subject to completion or amendment. A Registration Statement on Form 10 relating to these securities has been filed with the U.S. Securities and Exchange Commission under the U.S. Securities Exchange Act of 1934, as am

EX-99.1 3 ny20006220x5ex99-1.htm EXHIBIT 99.1 TABLE OF CONTENTS Exhibit 99.1   [   ], 2023 Dear MDU Resources Group, Inc. Stockholder: On August 4, 2022, we announced plans to separate our wholly owned subsidiary Knife River Corporation (“Knife River” or the “Company”) from MDU Resources Group, Inc. (“MDU Resources”). The separation will occur by means of a spinoff of a newly formed company named

February 3, 2023 EX-99.1

Information contained herein is subject to completion or amendment. A Registration Statement on Form 10 relating to these securities has been confidentially submitted to the U.S. Securities and Exchange Commission under the U.S. Securities Exchange A

EX-99.1 2 filename2.htm TABLE OF CONTENTS Exhibit 99.1   [   ], 2023 Dear MDU Resources Group, Inc. Stockholder: On August 4, 2022, we announced plans to separate our wholly owned subsidiary Knife River Corporation (“Knife River” or the “Company”) from MDU Resources Group, Inc. (“MDU Resources”). The separation will occur by means of a spinoff of a newly formed company named Knife River Holding Co

February 3, 2023 DRSLTR

- 9 -

[Letterhead of Wachtell, Lipton, Rosen & Katz] February 3, 2023 VIA EDGAR SUBMISSION Office of Energy & Transportation Division of Corporation Finance U.

February 3, 2023 DRS/A

As confidentially submitted to the U.S. Securities and Exchange Commission on February 3, 2023. This draft registration statement has not been publicly filed with the U.S. Securities and Exchange Commission and all information herein remains strictly

DRS/A 1 filename1.htm As confidentially submitted to the U.S. Securities and Exchange Commission on February 3, 2023. This draft registration statement has not been publicly filed with the U.S. Securities and Exchange Commission and all information herein remains strictly confidential. File No. 001-    UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Amendment No. 1 to FORM

December 14, 2022 EX-99.1

Information contained herein is subject to completion or amendment. A Registration Statement on Form 10 relating to these securities has been confidentially submitted to the U.S. Securities and Exchange Commission under the U.S. Securities Exchange A

EX-99.1 2 filename2.htm TABLE OF CONTENTS Exhibit 99.1   [   ], 2023 Dear MDU Resources Group, Inc. Stockholder: On August 4, 2022, we announced plans to separate our wholly owned subsidiary Knife River Corporation (“Knife River” or the “Company”) from MDU Resources Group, Inc. (“MDU Resources”). The separation will occur by means of a spinoff of a newly formed company named Knife River Holding Co

December 14, 2022 DRS

As confidentially submitted to the U.S. Securities and Exchange Commission on December 14, 2022. This draft registration statement has not been publicly filed with the U.S. Securities and Exchange Commission and all information herein remains strictl

DRS 1 filename1.htm As confidentially submitted to the U.S. Securities and Exchange Commission on December 14, 2022. This draft registration statement has not been publicly filed with the U.S. Securities and Exchange Commission and all information herein remains strictly confidential. File No. 001-    UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10 GENERAL FORM FOR

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