BKH / Black Hills Corporation - SEC-Einreichungen, Jahresbericht, Proxy Statement

Security Type

Calculation of Filing Fee Tables S-3 BLACK HILLS CORP /SD/ Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable 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 Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Fees Previously Paid Carry Forward Securities Carry Forward Securities 1 Equity Common stock, par value $1.

Security Type

Calculation of Filing Fee Tables S-3 BLACK HILLS CORP /SD/ Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable 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 Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Debt Debt Securities 457(r) 0.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTE

Exhibit 25.1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO SECTION 305(b)(2) [] Computershare Trust Company, National Association (Exact name of trustee as specified in its charter)

As filed with the Securities and Exchange Commission on May 19, 2026

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on May 19, 2026 Registration No.

securities and exchange commission Washington, D.C. 20549 FORM T-1 Statement of Eligibility Under The Trust Indenture Act of 1939 of a Corporation Designated to Act as Trustee Check if an Application to Determine Eligibility of a Trustee Pursuant to

Exhibit 25.2 securities and exchange commission Washington, D.C. 20549 FORM T-1 Statement of Eligibility Under The Trust Indenture Act of 1939 of a Corporation Designated to Act as Trustee Check if an Application to Determine Eligibility of a Trustee Pursuant to Section 305(b)(2) ¨ U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION (Exact name of Trustee as specified in its charter) 91-1821036 I.R.S. E

Up to $183.4 Million Common Stock

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(5)  Registration Statement No. 333-296010 PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED MAY 19, 2026 Up to $183.4 Million Common Stock We are party to a sales agreement originally dated June 16, 2023, as amended, with BofA Securities, Inc., BMO Capital Markets Corp., Mizuho Securities USA LLC, MUFG Securities Americas Inc. and RBC Capital Markets, LLC,

UNAUDITED PRO FORMA CONDENSED COMBINED CONSOLIDATED FINANCIAL INFORMATION

UNAUDITED PRO FORMA CONDENSED COMBINED CONSOLIDATED FINANCIAL INFORMATION On August 18, 2025, Black Hills Corporation, a South Dakota corporation (“Black Hills” or the “Company”), entered into an Agreement and Plan of Merger (the “Merger Agreement”) with NorthWestern Energy Group, Inc.

NORTHWESTERN ENERGY GROUP CONDENSED CONSOLIDATED STATEMENTS OF INCOME (in thousands, except per share amounts)

NORTHWESTERN ENERGY GROUP CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (in thousands, except per share amounts) Three Months Ended March 31, 2026 2025 Revenues Electric $ 362,054 $ 335,483 Gas 135,516 131,147 Total Revenues 497,570 466,630 Operating expenses Fuel, purchased supply and direct transmission expense (exclusive of depreciation and depletion shown separately below) 145,565 13

Item 8.01 Other Events. Item 9.01 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): May 15, 2026 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commissio

BLACK HILLS CORPORATION NON-EMPLOYEE DIRECTOR EQUITY COMPENSATION PLAN UNDER THE BLACK HILLS CORPORATION AMENDED AND RESTATED 2015 omnibus INCENTIVE PLAN Restricted Stock Unit Award Agreement (Non-Employee Director)

BLACK HILLS CORPORATION NON-EMPLOYEE DIRECTOR EQUITY COMPENSATION PLAN UNDER THE BLACK HILLS CORPORATION AMENDED AND RESTATED 2015 omnibus INCENTIVE PLAN Restricted Stock Unit Award Agreement (Non-Employee Director) Black Hills Corporation (the “Company”), pursuant to its Non-Employee Director Equity Compensation Plan (the “Non-Employee Director Equity Plan”) under its Amended and Restated 2015 Omnibus Incentive Plan (the “Omnibus Plan”), hereby grants an award of Restricted Stock Units to you, the Participant named below.

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, 2026 ☐ TRANSITION REPORT PURSUANT TO

Table of Contents 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, 2026 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 001-31303 Bla

Mine/ MSHA Identification Number

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

Item 2.02 Results of Operations and Financial Condition. Item 9.01 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): May 6, 2026 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commission

Three Months Ended March 31,

Black Hills Corp. Reaffirms 2026 Earnings Guidance, Reports 2026 First-Quarter Results, and Provides Updates on Merger with NorthWestern Energy and Data Center Progress • Reaffirms 2026 adjusted earnings guidance in the range of $4.25 to $4.45 per share, excluding merger-related costs • Served new all-time peak load at Wyoming Electric of 393 MW, reflecting an increase of 4% over 2025 peak • Execu

FORM 8-K Item 5.07 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): April 29, 2026 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commiss

FORM 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): April 02, 2026 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commiss

Black Hills Corp. and NorthWestern Energy Shareholders Approve Merger Proposals

Black Hills Corp. and NorthWestern Energy Shareholders Approve Merger Proposals RAPID CITY, SD and BUTTE, MT / SIOUX FALLS, SD — April 2, 2026 — Black Hills Corp. (NYSE: BKH) and NorthWestern Energy Group, Inc. d/b/a NorthWestern Energy (Nasdaq: NWE) announced today that shareholders of each company voted to approve the proposed all-stock merger and other related shareholder proposals at their Spe

ARS

2025 Annual Report | Proxy Statement | Form 10-K 2025 BLACK HILLS CORPORATIONWe are a customer-focused, growth-oriented utility company with a tradition of exemplary service and a vision to be the energy partner of choice.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A 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 Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ 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)(2)) ☒ Defini

UNAUDITED PRO FORMA CONDENSED COMBINED CONSOLIDATED FINANCIAL INFORMATION

UNAUDITED PRO FORMA CONDENSED COMBINED CONSOLIDATED FINANCIAL INFORMATION On August 18, 2025, Black Hills Corporation, a South Dakota corporation (“Black Hills” or the “Company”), entered into an Agreement and Plan of Merger (the “Merger Agreement”) with NorthWestern Energy Group, Inc.

Item 8.01 Other Events. Item 9.01 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): February 19, 2026 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Comm

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM To the shareholders and the Board of Directors of NorthWestern Energy Group, Inc.

7001 Mount Rushmore Road Rapid City, South Dakota 57702

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(3)  Registration No. 333-293105 7001 Mount Rushmore Road Rapid City, South Dakota 57702 3010 W. 69th Street Sioux Falls, South Dakota 57108 TRANSACTION PROPOSED — YOUR VOTE IS VERY IMPORTANT February 6, 2026 Dear Shareholders: On behalf of the boards of directors and management teams of Black Hills Corporation (“Black Hills”) and NorthWestern Energy

Black Hills Corp (Q4 2025 Earnings) February 5, 2026

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

Item 2.02 Results of Operations and Financial Condition. Item 9.01 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): Feb. 4, 2026 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commissio

Three Months Ended Dec. 31,

Black Hills Corp. Reports 2025 Fourth-Quarter and Full-Year Results and Initiates 2026 Earnings Guidance • Delivered 2025 GAAP EPS of $3.98 and adjusted EPS of $4.10, at midpoint of earnings guidance range • Initiates 2026 adjusted EPS guidance in the range of $4.25 to $4.45, reflecting 6% growth over 2025 • Advancing plans to serve data center pipeline of more than 3 GW, including 600 MW in five-

2025 Fourth Quarter and Full Year Review Feb. 5, 2026

2025 Fourth Quarter and Full Year Review Feb. 5, 2026 Forward-looking Statements COMPANY INFORMATION Black Hills Corporation P.O. Box 1400 Rapid City, SD 57709-1400 NYSE Ticker: BKH www.blackhillscorp.com Company Contacts Kimberly Nooney Senior Vice President and CFO 605-721-2370 [email protected] Sal Diaz Director of Investor Relations 605-399-5079 [email protected] This pre

CONSENT OF GREENHILL & CO., LLC

Exhibit 99.4 CONSENT OF GREENHILL & CO., LLC January 30, 2026 Board of Directors NorthWestern Energy Group, Inc. 3010 West 69th Street Sioux Falls, South Dakota 57108 Members of the Board of Directors: We hereby consent to the inclusion of our opinion letter, dated August 18, 2025, to the Board of Directors of NorthWestern Energy Group, Inc. (“NorthWestern”) as Annex C to, and to the description o

Black Hills Corporation 7001 Mount Rushmore Road Rapid City, South Dakota 57702 ADVANCE NOTICE OF SPECIAL MEETING OF SHAREHOLDERS

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

Important Notice Regarding the Availability of Proxy Materials for the Special Meeting: The Proxy Statement is available at www.proxyvote.com. V83640-S31573 NORTHWESTERN ENERGY 3010 W. 69TH STREET, SIOUX FALLS, SD 57108 PROXY FOR THE SPECIAL MEETING

Exhibit 99.2 Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) Date TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS: KEEP THIS PORTION FOR YOUR RECORDS DETACH AND RETURN THIS PORTION ONLY THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. V83639-S31573 For Against Abstain ! ! ! ! ! ! ! ! ! The Board of Directors recommends you vote FOR the following proposals: NORTHWEST

Consent to be Named as a Director

Exhibit 99.6 Consent to be Named as a Director In connection with the filing by Black Hills Corporation of the Registration Statement on Form S-4 (the “Registration Statement”) with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), I hereby consent, pursuant to Rule 438 of the Securities Act, to being named in the Registration Statement and

Security Type

Calculation of Filing Fee Tables S-4 BLACK HILLS CORP /SD/ Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable 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 Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Equity Common Stock, Par Value $1.

Consent to be Named as a Director

Exhibit 99.5 Consent to be Named as a Director In connection with the filing by Black Hills Corporation of the Registration Statement on Form S-4 (the “Registration Statement”) with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), I hereby consent, pursuant to Rule 438 of the Securities Act, to being named in the Registration Statement and

Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) Date TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS: KEEP THIS PORTION FOR YOUR RECORDS DETACH AND RETURN THIS PORTION ONLY THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DAT

Exhibit 99.1 Signature [PLEASE SIGN WITHIN BOX] Date Signature (Joint Owners) Date TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS: KEEP THIS PORTION FOR YOUR RECORDS DETACH AND RETURN THIS PORTION ONLY THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED. BLACK HILLS CORPORATION Please sign exactly as your name(s) appear(s) hereon. When signing as attorney, executor, administrator, or o

As filed with the U.S. Securities and Exchange Commission on January 30, 2026

TABLE OF CONTENTS As filed with the U.S. Securities and Exchange Commission on January 30, 2026 Registration No. 333-      UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-4 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota 4911 46-0458824 (State or other jurisdiction of

January 30, 2026

Exhibit 99.3 January 30, 2026 Board of Directors Black Hills Corporation 7001 Mount Rushmore Road Rapid City, SD 57701 Re: Initially Filed Registration Statement on Form S-4 of Black Hills Corporation (File No. 333-      ), filed January 30, 2026 (the “Registration Statement”) Ladies and Gentlemen: Reference is made to our opinion letter, dated August 18, 2025 (“Opinion Letter”), with respect to t

Black Hills Corporation (Q3 2025 Earnings) November 6, 2025

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

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, 2025 ☐ TRANSITION REPORT PURSUANT

Table of Contents 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, 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 001-31303

AMENDED AND RESTATED BYLAWS OF BLACK HILLS CORPORATION ARTICLE I MEETINGS OF SHAREHOLDERS

AMENDED AND RESTATED BYLAWS OF BLACK HILLS CORPORATION ARTICLE I MEETINGS OF SHAREHOLDERS Section 1.

Mine/ MSHA Identification Number

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

Item 2.02 Results of Operations and Financial Condition. Item 9.01 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): Nov. 5, 2025 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commissio

2025 Third Quarter Review Nov. 6, 2025

2025 Third Quarter Review Nov. 6, 2025 Forward-looking Statements COMPANY INFORMATION Black Hills Corporation P.O. Box 1400 Rapid City, SD 57709-1400 NYSE Ticker: BKH www.blackhillscorp.com Company Contacts Kimberly Nooney Senior Vice President and CFO 605-721-2370 [email protected] Sal Diaz Director of Investor Relations 605-399-5079 [email protected] This presentation inclu

Three Months Ended Sept. 30,

Black Hills Corp. Reports 2025 Third-Quarter Results and Reaffirms 2025 Adjusted Earnings Guidance • Reaffirms 2025 adjusted earnings guidance in the range of $4.00 to $4.20 per share, excluding merger-related costs, same as prior GAAP guidance • Completed planned equity and debt financing activities for 2025 • Filed settlement agreement for new customer rates at Nebraska natural gas utility • Com

As confidentially submitted to the Securities and Exchange Commission on October 30, 2025. This draft registration statement has not been publicly filed and all information herein remains strictly confidential.

TABLE OF CONTENTS As confidentially submitted to the Securities and Exchange Commission on October 30, 2025.

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): October 2, 2025 Black Hills 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): October 2, 2025 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commis

BLACK HILLS CORPORATION COMPUTERSHARE TRUST COMPANY, N.A., AS TRUSTEE FOURTEENTH SUPPLEMENTAL INDENTURE DATED AS OF October 2, 2025 $450,000,000 4.550% NOTES DUE 2031

Exhibit 4.1 Execution Version BLACK HILLS CORPORATION AND COMPUTERSHARE TRUST COMPANY, N.A., AS TRUSTEE FOURTEENTH SUPPLEMENTAL INDENTURE DATED AS OF October 2, 2025 $450,000,000 4.550% NOTES DUE 2031 FOURTEENTH SUPPLEMENTAL INDENTURE dated as of October 2, 2025 (this “Supplemental Indenture”), to the Indenture dated as of May 21, 2003 (the “Base Indenture” and, as supplemented by the First Supple

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): September 25, 2025 Black Hills Co

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): September 25, 2025 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Com

Black Hills Corporation $450,000,000 4.550% Notes due 2031 UNDERWRITING AGREEMENT

Exhibit 1.1 Black Hills Corporation $450,000,000 4.550% Notes due 2031 UNDERWRITING AGREEMENT September 25, 2025 J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 As Representative (the “Representative”) of the Several Underwriters Ladies and Gentlemen: 1. Introductory. Black Hills Corporation, a South Dakota corporation (the “Company”), agrees with the several Underwriters na

Security Type

Calculation of Filing Fee Tables S-3 BLACK HILLS CORP /SD/ Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable 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 Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Debt 4.

PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED JUNE 16, 2023 $450,000,000 4.550% Notes due 2031

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(2)  Registration Statement No. 333-272739 PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED JUNE 16, 2023 $450,000,000 4.550% Notes due 2031 Black Hills Corporation is offering $450,000,000 aggregate principal amount of 4.550% Notes due 2031 (the “Notes”). We will pay interest on the Notes on January 31 and July 31 of each year, beginning on January 31, 202

SUBJECT TO COMPLETION, DATED SEPTEMBER 25, 2025 PRELIMINARY PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED JUNE 16, 2023 $         % Notes due 20  

TABLE OF CONTENTS The information in this preliminary prospectus supplement is not complete and may be changed.

Black Hills Corporation

Filed Pursuant to Rule 433 Registration No. 333-272739 Pricing Term Sheet September 25, 2025 Black Hills Corporation This communication should be read in conjunction with the preliminary prospectus supplement dated September 25, 2025 and the accompanying base prospectus. The information in this communication supersedes the information in the preliminary prospectus supplement and the accompanying b

Item 8.01 Other Events. Item 9.01 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): September 15, 2025 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Com

UNAUDITED PRO FORMA CONDENSED COMBINED CONSOLIDATED FINANCIAL INFORMATION

UNAUDITED PRO FORMA CONDENSED COMBINED CONSOLIDATED FINANCIAL INFORMATION On August 18, 2025, Black Hills Corporation, a South Dakota corporation (“Black Hills” or the “Company”), entered into an Agreement and Plan of Merger (the “Merger Agreement”) with NorthWestern Energy Group, Inc.

NORTHWESTERN ENERGY GROUP

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM To the shareholders and the Board of Directors of NorthWestern Energy Group, Inc.

Supplementary Risk Factors

Supplementary Risk Factors Unless these supplemental risk factors indicate otherwise, or the context otherwise requires, references to the term “Black Hills” means Black Hills Corporation and “NorthWestern” means NorthWestern Energy Group, Inc.

NORTHWESTERN ENERGY GROUP CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE AND SIX MONTHS ENDED JUNE 30, 2025 NORTHWESTERN ENERGY GROUP CONDENSED CONSOLIDATED STATEMENTS OF INCOME (in thousands, except per share amounts)

NORTHWESTERN ENERGY GROUP CONSOLIDATED FINANCIAL STATEMENTS FOR THE THREE AND SIX MONTHS ENDED JUNE 30, 2025 NORTHWESTERN ENERGY GROUP CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (in thousands, except per share amounts) Three Months Ended June 30, Six Months Ended June 30, 2025 2024 2025 2024 Revenues Electric $ 279,468 $ 260,134 $ 614,951 $ 603,320 Gas 63,245 59,795 194,392 191,951 To

Filed by Black Hills Corporation

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

CHIEF EXECUTIVE OFFICER AGREEMENT

Exhibit 10.1 CHIEF EXECUTIVE OFFICER AGREEMENT This CHIEF EXECUTIVE OFFICER AGREEMENT (the “Agreement”) is made by and between Black Hills Corporation, a South Dakota corporation (hereinafter the “Company”), and Brian B. Bird (the “Executive”), dated as of August 18, 2025 and effective as of the Effective Time (as defined in the Merger Agreement referred to below); WHEREAS, reference is made to th

Creating a premier regional regulated electric and natural gas utility company + Black Hills Corp. and NorthWestern Energy to Combine Forward + 2 -Looking Statements Information in this communication, other than statements of historical facts, may co

Exhibit 99.2 Creating a premier regional regulated electric and natural gas utility company + Black Hills Corp. and NorthWestern Energy to Combine Forward + 2 -Looking Statements Information in this communication, other than statements of historical facts, may constitute forward-looking statements, within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the

2

Exhibit 10.2 August 18, 2025 Linden R. Evans Dear Linn: Per our discussions, you and Black Hills Corporation (the “Company”), have agreed to certain matters pertaining your service as the President and Chief Executive Officer of the Company. The purpose of this letter agreement (the “Letter Agreement”) is to formalize those terms. Pursuant to an Agreement and Plan of Merger (such Agreement and Pla

Filed by Black Hills Corporation

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

Filed by Black Hills Corporation

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

BLACK HILLS CORPORATION AMENDMENT TO AMENDED AND RESTATED BYLAWS

Exhibit 3.1 BLACK HILLS CORPORATION AMENDMENT TO AMENDED AND RESTATED BYLAWS Section 3 of Article II of the Amended and Restated Bylaws of Black Hills Corporation, dated as of April 24, 2023 (the “Bylaws”) is hereby deleted in its entirety and replaced with the following: Section 3. Qualifications of Directors. Restrictions and qualifications for Directors may be fixed from time to time in the Cor

Filed by Black Hills Corporation

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

Filed by Black Hills Corporation

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

AGREEMENT AND PLAN OF MERGER by and among Black Hills Corporation Northwestern Energy Group, Inc. River Merger Sub Inc. Dated as of August 18, 2025 TABLE OF CONTENTS

Exhibit 2.1 AGREEMENT AND PLAN OF MERGER by and among Black Hills Corporation Northwestern Energy Group, Inc. and River Merger Sub Inc. Dated as of August 18, 2025 TABLE OF CONTENTS Article I THE MERGER 2 Section 1.01 The Merger 2 Section 1.02 The Closing 2 Section 1.03 The Effective Time 2 Section 1.04 Effects of the Merger 3 Section 1.05 Organizational Documents 3 Section 1.06 Directors and Offi

BLACK HILLS CORPORATION AMENDMENT TO AMENDED AND RESTATED BYLAWS

Exhibit 3.1 BLACK HILLS CORPORATION AMENDMENT TO AMENDED AND RESTATED BYLAWS Section 3 of Article II of the Amended and Restated Bylaws of Black Hills Corporation, dated as of April 24, 2023 (the “Bylaws”) is hereby deleted in its entirety and replaced with the following: Section 3. Qualifications of Directors. Restrictions and qualifications for Directors may be fixed from time to time in the Cor

For Internal Use Only. Not for Distribution.

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

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 18, 2025 Black Hills 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 18, 2025 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota 001-31303 46-0458824 (State or other jurisdiction of incorporation) (Commis

Filed by Black Hills Corporation

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

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Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

Black Hills Corp. + NorthWestern Energy Creating a Premier Regional Regulated Electric and Natural Gas Utility Company Pure-Play Utility Platform Across Eight Contiguous States Regionally diverse, vertically integrated regulated electric and natural

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

AGREEMENT AND PLAN OF MERGER by and among Black Hills Corporation Northwestern Energy Group, Inc. River Merger Sub Inc. Dated as of August 18, 2025 TABLE OF CONTENTS

Exhibit 2.1 AGREEMENT AND PLAN OF MERGER by and among Black Hills Corporation Northwestern Energy Group, Inc. and River Merger Sub Inc. Dated as of August 18, 2025 TABLE OF CONTENTS Article I THE MERGER 2 Section 1.01 The Merger 2 Section 1.02 The Closing 2 Section 1.03 The Effective Time 2 Section 1.04 Effects of the Merger 3 Section 1.05 Organizational Documents 3 Section 1.06 Directors and Offi

Creating a premier regional regulated electric and natural gas utility company + Black Hills Corp. and NorthWestern Energy to Combine Forward + 2 -Looking Statements Information in this communication, other than statements of historical facts, may co

Exhibit 99.2 Creating a premier regional regulated electric and natural gas utility company + Black Hills Corp. and NorthWestern Energy to Combine Forward + 2 -Looking Statements Information in this communication, other than statements of historical facts, may constitute forward-looking statements, within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the

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 19, 2025 Black Hills 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 19, 2025 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota 001-31303 46-0458824 (State or other jurisdiction of incorporation) (Commis

CHIEF EXECUTIVE OFFICER AGREEMENT

Exhibit 10.1 CHIEF EXECUTIVE OFFICER AGREEMENT This CHIEF EXECUTIVE OFFICER AGREEMENT (the “Agreement”) is made by and between Black Hills Corporation, a South Dakota corporation (hereinafter the “Company”), and Brian B. Bird (the “Executive”), dated as of August 18, 2025 and effective as of the Effective Time (as defined in the Merger Agreement referred to below); WHEREAS, reference is made to th

Black Hills Corp. + NorthWestern Energy Creating a Premier Regional Regulated Electric and Natural Gas Utility Company + Regionally Diverse, Vertically Integrated Regulated Electric and Natural Gas Utility of Scale For more information: www.BlackHill

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

Creating a premier regional regulated electric and natural gas utility company + Black Hills Corp. and NorthWestern Energy to Combine + 2 Black Hills Gas Utility Service Territory Black Hills HQ Black Hills Electric Utility Service Territory NorthWes

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

Black Hills Corp. and NorthWestern Energy to Combine in All-Stock Merger to Create a Premier Regional Regulated Electric and Natural Gas Utility Company Increased scale and business line diversity to result in a stronger, more resilient platform to s

Exhibit 99.1 Black Hills Corp. and NorthWestern Energy to Combine in All-Stock Merger to Create a Premier Regional Regulated Electric and Natural Gas Utility Company Increased scale and business line diversity to result in a stronger, more resilient platform to safely, reliably, and cost-effectively meet customers’ rising energy needs Merger expected to be accretive to each company’s EPS in the fi

2

Exhibit 10.2 August 18, 2025 Linden R. Evans Dear Linn: Per our discussions, you and Black Hills Corporation (the “Company”), have agreed to certain matters pertaining your service as the President and Chief Executive Officer of the Company. The purpose of this letter agreement (the “Letter Agreement”) is to formalize those terms. Pursuant to an Agreement and Plan of Merger (such Agreement and Pla

Black Hills Corp. and NorthWestern Energy to Combine in All-Stock Merger to Create a Premier Regional Regulated Electric and Natural Gas Utility Company Increased scale and business line diversity to result in a stronger, more resilient platform to s

Exhibit 99.1 Black Hills Corp. and NorthWestern Energy to Combine in All-Stock Merger to Create a Premier Regional Regulated Electric and Natural Gas Utility Company Increased scale and business line diversity to result in a stronger, more resilient platform to safely, reliably, and cost-effectively meet customers’ rising energy needs Merger expected to be accretive to each company’s EPS in the fi

Filed by Black Hills Corporation

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

Filed by Black Hills Corporation

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

Filed by Black Hills Corporation

Filed by Black Hills Corporation pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 under the Securities Exchange Act of 1934 Subject Company: NorthWestern Energy Group, Inc.

Black Hills Corp. and NorthWestern Energy to Combine in All-Stock Merger to Create a Premier Regional Regulated Electric and Natural Gas Utility Company Increased scale and business line diversity to result in a stronger, more resilient platform to s

Exhibit 99.1 Black Hills Corp. and NorthWestern Energy to Combine in All-Stock Merger to Create a Premier Regional Regulated Electric and Natural Gas Utility Company Increased scale and business line diversity to result in a stronger, more resilient platform to safely, reliably, and cost-effectively meet customers’ rising energy needs Merger expected to be accretive to each company’s EPS in the fi

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 18, 2025 Black Hills 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 18, 2025 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota 001-31303 46-0458824 (State or other jurisdiction of incorporation) (Commis

Creating a premier regional regulated electric and natural gas utility company + Black Hills Corp. and NorthWestern Energy to Combine Forward + 2 -Looking Statements Information in this communication, other than statements of historical facts, may co

Exhibit 99.2 Creating a premier regional regulated electric and natural gas utility company + Black Hills Corp. and NorthWestern Energy to Combine Forward + 2 -Looking Statements Information in this communication, other than statements of historical facts, may constitute forward-looking statements, within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

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

Table of Contents 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 001-31303 Blac

Item 2.02 Results of Operations and Financial Condition. Item 9.01 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): July 30, 2025 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commissi

Three Months Ended June 30,

Black Hills Corp. Reaffirms 2025 Earnings Guidance and Reports 2025 Second-Quarter Results • Reaffirms 2025 earnings guidance range of $4.00 to $4.20 per share • Established Emergency Public Safety Power Shutoff (PSPS) program • Received approval for new rates at Kansas Gas providing $10.8 million of new annual revenues • Received CPCN for South Dakota Electric’s 99-megawatt generation project • S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 11-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 11-K x 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 File Number 001-31303 A. Full title of the

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): May 8, 2025 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commission

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 7, 2025 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commission

Three Months Ended March 31,

Black Hills Corp. Reaffirms 2025 Earnings Guidance and Reports 2025 First-Quarter Results • Reaffirms 2025 earnings guidance range of $4.00 to $4.20 per share with strong confidence in 4-6% EPS growth rate outlook • Obtained all rights-of-way for 260-mile electric transmission expansion in Wyoming that will provide long-term cost stability for customers and enable growth • Served new all-time peak

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

Table of Contents 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 001-31303 Bla

First Amendment to Equity Distribution Sales Agreement dated May 8, 2025 among Black Hills Corporation and the Agents, Forward Purchasers and Forward Sellers named therein.

Exhibit 1.1 FIRST AMENDMENT TO EQUITY DISTRIBUTION SALES AGREEMENT This First Amendment (the “Amendment”), entered into as of May 8, 2025, to that certain Equity Distribution Sales Agreement (the “Sales Agreement”), dated as of June 16, 2023, among Black Hills Corporation, a South Dakota corporation (the “Company”) and each of Bank of Montreal, Bank of America, N.A., MUFG Securities EMEA plc, Mizu

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

Up to $400,000,000 Common Stock

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(5)  Registration Statement No. 333-272739 PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED JUNE 16, 2023 Up to $400,000,000 Common Stock We have entered into a sales agreement with BofA Securities, Inc., BMO Capital Markets Corp., Mizuho Securities USA LLC, MUFG Securities Americas Inc. and RBC Capital Markets, LLC, as our sales agents and as forward selle

Table 1: Newly Registered and Carry Forward Securities

Calculation of Filing Fee Tables S-3 BLACK HILLS CORP /SD/ 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 Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Equity Common stock, par value $1.

FORM 8-K Item 5.07 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): April 23, 2025 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commiss

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A 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 Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ 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)(2)) ☒ Defini

ARS

2024 Annual Report | Proxy Statement | Form 10-K BLACK HILLS 2024 CORPORATIONWe are a customer-focused, growth-oriented utility company with a tradition of exemplary service and a vision to be the energy partner of choice.

List of Subsidiaries of Black Hills Corporation.

Exhibit 21 BLACK HILLS CORPORATION SUBSIDIARIES December 31, 2024 Subsidiary Name State of Origin 1.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 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 SECTION

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 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 001-31303 BLACK HILLS CORPORATION Incorporated in South Dakota IRS Identification Number 46-0458824 7001 Mount Rushmore Road Rapid City, South Dakota 57702 Registrant’s telephone number (605) 721-1700 Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol Name of each exchange on which registered Common stock of $1.

Exhibit 95

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

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

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 31, 2025 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commi

EX-99

EX-99 3 ITEM7.txt EXHIBIT 99: ITEM 7 BlackRock Life Limited BlackRock Advisors, LLC Aperio Group, LLC BlackRock (Netherlands) B.V. BlackRock Fund Advisors* BlackRock Institutional Trust Company, National Association BlackRock Asset Management Ireland Limited BlackRock Financial Management, Inc. BlackRock Investment Management, LLC BlackRock Investment Management (UK) Limited SpiderRock Advisors, L

EX-24

EX-24 2 PowerOfAttorney.txt EXHIBIT 24: POWER OF ATTORNEY POWER OF ATTORNEY The undersigned, BlackRock, Inc., a corporation duly organized under the laws of the State of Delaware, United States (the "Company"), does hereby make, constitute and appoint each of Eric Andruczyk, Richard Cundiff, R. Andrew Dickson, III, Spencer Fleming, Laura Hildner, David Maryles, Christopher Meade, Charles Park, Jam

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): Feb. 5, 2025 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commissio

Three Months Ended Dec. 31,

Black Hills Corp. Reports 2024 Fourth-Quarter and Full-Year Results and Initiates 2025 Earnings Guidance • Delivered 2024 EPS of $3.91, or 4.3% growth from the midpoint of 2023 earnings guidance • Increasing five-year capital forecast by 10% to $4.7 billion for 2025 through 2029, including $1.0 billion for 2025 • Projecting total data center load exceeding one gigawatt from existing customers • In

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

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

Table of Contents 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 001-31303

Three Months Ended Sept. 30,

Black Hills Corp. Reaffirms 2024 Earnings Guidance and Reports 2024 Third-Quarter Results • Reaffirms 2024 earnings guidance range of $3.80 to $4.00 per share • Received approval of and implemented new customer rates at Arkansas natural gas utility • Filed settlement agreement for new customer rates at Iowa natural gas utility • Completed key financing activities for 2024 and achieved long-term ca

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): Nov. 6, 2024 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commissio

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

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): October 28, 2024 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commi

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

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 09, 2024 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commis

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

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

Table of Contents 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 001-31303 Blac

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): July 31, 2024 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commissi

Three Months Ended June 30,

Black Hills Corp. Reports 2024 Second-Quarter Results and Reaffirms 2024 Earnings Guidance RAPID CITY, S.D. — July 31, 2024 — Black Hills Corp. (NYSE: BKH) today announced financial results for the second quarter of 2024. Net income available for common stock and earnings per share for the three and six months ended June 30, 2024, compared to the three and six months ended June 30, 2023, were: Thr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 11-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 11-K x 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 001-31303 A. Full title of the

Second Amendment to Fourth Amended and Restated Credit Agreement dated as of May 31, 2024 (relating to $750 million Revolving Credit Facility), among Black Hills Corporation, as Borrower, the financial institutions party there, as Banks, and U.S. Bank, National Association, as Administrative Agent.

Execution Version SECOND AMENDMENT TO FOURTH AMENDED AND RESTATED CREDIT AGREEMENT THIS SECOND AMENDMENT TO FOURTH AMENDED AND RESTATED CREDIT AGREEMENT (this “Amendment”) is made as of May 31, 2024 (the “Effective Date”) by and among BLACK HILLS CORPORATION, a South Dakota corporation (the “Borrower”), the financial institutions listed on the signature pages hereto (the “Banks”) and U.

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

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 31, 2024 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commissio

Underwriting Agreement dated as of May 13, 2024 between Black Hills Corporation and the underwriters named therein.

Exhibit 1.1 Execution Version Black Hills Corporation $450,000,000 6.000% Notes due 2035 UNDERWRITING AGREEMENT May 13, 2024 Wells Fargo Securities, LLC 550 South Tryon St., 5th Floor Charlotte, NC 28202 BofA Securities, Inc. One Bryant Park New York, NY, 10036 As Representatives (the “Representatives”) of the Several Underwriters Ladies and Gentlemen: 1. Introductory. Black Hills Corporation, a S

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): May 13, 2024 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commissio

Thirteenth Supplemental Indenture dated as of May 16, 2024, (filed as Exhibit 4.1 to the Registrant's Form 8-K filed on May 16, 2024).

Exhibit 4.1 Execution Version BLACK HILLS CORPORATION AND COMPUTERSHARE TRUST COMPANY, N.A., AS TRUSTEE THIRTEENTH SUPPLEMENTAL INDENTURE DATED AS OF May 16, 2024 $450,000,000 6.000% NOTES DUE 2035 THIRTEENTH SUPPLEMENTAL INDENTURE dated as of May 16, 2024 (this “Supplemental Indenture”), to the Indenture dated as of May 21, 2003 (the “Base Indenture” and, as supplemented by the First Supplemental

PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED JUNE 16, 2023 $450,000,000 6.000% Notes due 2035

TABLE OF CONTENTS   Filed Pursuant to Rule 424(b)(2)  Registration Statement No. 333-272739 PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED JUNE 16, 2023 $450,000,000 6.000% Notes due 2035 Black Hills Corporation is offering $450,000,000 aggregate principal amount of 6.000% Notes due 2035 (the “Notes”). We will pay interest on the Notes on January 15 and July 15 of each year, beginning on January 15, 20

Calculation of Filing Fee Table FORM S-3 (Form Type) BLACK HILLS CORPORATION (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities

Exhibit 107 Calculation of Filing Fee Table FORM S-3 (Form Type) BLACK HILLS 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 Debt 6.

Black Hills Corporation

Filed Pursuant to Rule 433 Registration No. 333-272739 Pricing Term Sheet May 13, 2024 Black Hills Corporation This communication should be read in conjunction with the preliminary prospectus supplement dated May 13, 2024 and the accompanying base prospectus. The information in this communication supersedes the information in the preliminary prospectus supplement and the accompanying base prospect

SUBJECT TO COMPLETION, DATED MAY 13, 2024 PRELIMINARY PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED JUNE 16, 2023 $           % Notes due 20

TABLE OF CONTENTS The information in this preliminary prospectus supplement is not complete and may be changed.

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

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

Table of Contents 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 001-31303 Bla

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 8, 2024 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commission

Three Months Ended March 31,

Black Hills Corp. Reports 2024 First-Quarter Results and Reaffirms 2024 Earnings Guidance RAPID CITY, S.D. — May 8, 2024 — Black Hills Corp. (NYSE: BKH) today announced financial results for the first quarter of 2024. Net income available for common stock and earnings per share for the three months ended March 31, 2024, compared to the three months ended March 31, 2023, were: Three Months Ended Ma

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): April 23, 2024 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commiss

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

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): April 24, 2024 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commiss

ARS

2023 Annual Report | Proxy Statement | Form 10-K BLACK HILLS 2023 CORPORATIONWe are a customer focused, growth-oriented utility company with a tradition of exemplary service and a vision to be the energy partner of choice.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A 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 Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ 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)(2)) ☒ Defini

Form of Short-term Incentive Plan Award Agreement for the Amended and Restated 2015 Omnibus Incentive Plan effective for awards granted on or after January 1, 2024.

Black Hills Corporation Short-Term Incentive Plan Award Agreement (Effective for Plan Years Beginning on or after January 1, 2024) You have been selected to be a Participant in the Black Hills Corporation Short-Term Incentive Plan (the “STIP”).

Insider Trading Policy

BLACK HILLS CORPORATION COMPANY POLICY Affected Business Unit(s): All Originating Department(s): Governance Effective Date: 12-07-2011 Policy No.

Form of Performance Unit Award Agreement for the Amended and Restated 2015 Omnibus Incentive Plan effective for awards granted on or after January 1, 2024.

Black Hills Corporation Long-Term Incentive Plan Performance Unit Award Agreement Performance Period - January 1, 2024 – December 31, 2026 You have been selected to be a Participant in the Black Hills Corporation Long-Term Incentive Plan (the “LTIP”).

Mandatory Compensation Recovery Policy dated December 1, 2023

BLACK HILLS CORPORATION POLICY Affected Business Unit(s): Originating Department(s): Governance All Effective Date: December 1, 2023 Policy No.

List of Subsidiaries of Black Hills Corporation.

Exhibit 21 BLACK HILLS CORPORATION SUBSIDIARIES December 31, 2023 Subsidiary Name State of Origin 1.

Mine Safety and Health Administration Safety Data

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 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 SECTION

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 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 001-31303 BLACK HILLS CORPORATION Incorporated in South Dakota IRS Identification Number 46-0458824 7001 Mount Rushmore Road Rapid City, South Dakota 57702 Registrant’s telephone number (605) 721-1700 Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol Name of each exchange on which registered Common stock of $1.

BKH / Black Hills Corporation / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv0027-blackhillscorp.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 13)* Name of issuer: Black Hills Corp Title of Class of Securities: Common Stock CUSIP Number: 092113109 Date of Event Which Requires Filing of this Statement: December 29, 2023 Check the appropriate box to designate th

Three Months Ended Dec. 31,

Black Hills Corp. Reports 2023 Fourth-Quarter and Full-Year Results and Initiates 2024 Earnings Guidance • Delivered EPS of $3.91, above earnings guidance range of $3.65 to $3.85 • Improved year-over-year total net debt to capitalization ratio to 57.3% from 60.8% • Increased quarterly dividend, extending annual dividend increase track record to 54 consecutive years • Initiating 2024 EPS guidance r

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): Feb. 7, 2024 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commissio

BKH / Black Hills Corporation / STATE STREET CORP Passive Investment

SC 13G/A 1 BlackHillsCorp.txt UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 AMENDED FILING BLACK HILLS CORP (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 092113109 (CUSIP NUMBER) 12/31/2023 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT T

BKH / Black Hills Corporation / BlackRock Inc. Passive Investment

SC 13G/A 1 us0921131092012224.txt us0921131092012224.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 15) BLACK HILLS CORPORATION - (Name of Issuer) Common Stock - (Title of Class of Securities) 092113109 - (CUSIP Number) December 31, 2023 - (Date of Event Which Requires Filing of this Statement) Check the appropria

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

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

Table of Contents 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 001-31303

Three Months Ended Sept. 30,

Black Hills Corp. Reports 2023 Third-Quarter Results and Reaffirms 2023 Earnings Guidance RAPID CITY, S.D. — Nov. 1, 2023 — Black Hills Corp. (NYSE: BKH) today announced financial results for the third quarter of 2023. Net income available for common stock and earnings per share for the three and nine months ended Sept. 30, 2023, compared to the three and nine months ended Sept. 30, 2022, were: Th

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 1, 2023 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commi

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): September 15, 2023 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota 001-31303 46-0458824 (State or other jurisdiction of incorporation) (Com

Twelfth Supplemental Indenture dated as of September 15, 2023 between Black Hills Corporation and Computershare Trust Company, N.A. (as current successor to LaSalle Bank National Association), as trustee.

Exhibit 4.1 Execution Version BLACK HILLS CORPORATION AND COMPUTERSHARE TRUST COMPANY, N.A., AS TRUSTEE TWELFTH SUPPLEMENTAL INDENTURE DATED AS OF SEPTEMBER 15, 2023 $450,000,000 6.150% NOTES DUE 2034 TWELFTH SUPPLEMENTAL INDENTURE dated as of September 15, 2023 (this “Supplemental Indenture”), to the Indenture dated as of May 21, 2003 (the “Base Indenture” and, as supplemented by the First Supple

Underwriting Agreement dated as of September 6, 2023 between Black Hills Corporation and the underwriters named therein.

Exhibit 1.1 Execution Version Black Hills Corporation $450,000,000 6.150% Notes due 2034 UNDERWRITING AGREEMENT September 6, 2023 MUFG Securities Americas Inc. 1221 Avenue of the Americas, 6th Floor New York, NY, 10020-1001 Scotia Capital (USA) Inc. 250 Vesey Street New York, NY 10281 As Representatives (the “Representatives”) of the Several Underwriters Ladies and Gentlemen: 1. Introductory. Blac

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): September 6, 2023 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota 001-31303 46-0458824 (State or other jurisdiction of incorporation) (Comm

PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED JUNE 16, 2023 $450,000,000 6.150% Notes due 2034

TABLE OF CONTENTS   Filed Pursuant to Rule 424(b)(2)  Registration Statement No. 333-272739 PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED JUNE 16, 2023 $450,000,000 6.150% Notes due 2034 Black Hills Corporation is offering $450,000,000 aggregate principal amount of 6.150% Notes due 2034 (the “Notes”). We will pay interest on the Notes on May 15 and November 15 of each year, beginning on May 15, 2024.

Calculation of Filing Fee Table FORM S-3 (Form Type) BLACK HILLS CORPORATION (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities

Exhibit 107 Calculation of Filing Fee Table FORM S-3 (Form Type) BLACK HILLS 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 Debt 6.

SUBJECT TO COMPLETION, DATED September 6, 2023 PRELIMINARY PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED JUNE 16, 2023 $           % Notes due 20

TABLE OF CONTENTS The information in this preliminary prospectus supplement is not complete and may be changed.

Black Hills Corporation

Filed Pursuant to Rule 433 Registration No. 333-272739 Pricing Term Sheet September 6, 2023 Black Hills Corporation This communication should be read in conjunction with the preliminary prospectus supplement dated September 6, 2023 and the accompanying base prospectus. The information in this communication supersedes the information in the preliminary prospectus supplement and the accompanying bas

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

Table of Contents 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 001-31303 Blac

First Amendment to Fourth Amended and Restated Credit Agreement dated as of May 9, 2023 (relating to $750 million Revolving Credit Facility), among Black Hills Corporation, as Borrower, the financial institutions party thereto, as Banks, and U.S. Bank, National Association, as Administrative Agent.

Execution Version FIRST AMENDMENT TO FOURTH AMENDED AND RESTATED CREDIT AGREEMENT THIS FIRST AMENDMENT TO FOURTH AMENDED AND RESTATED CREDIT AGREEMENT (this “Amendment”) is made as of May 9, 2023 (the “Effective Date”) by and among BLACK HILLS CORPORATION, a South Dakota corporation (the “Borrower”), the financial institutions listed on the signature pages hereto (the “Banks”) and U.

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

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 2, 2023 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commiss

Three Months Ended June 30,

Black Hills Corp. Reports 2023 Second-Quarter Results and Reaffirms 2023 Earnings Guidance • Strengthened balance sheet and maintained robust liquidity • Issued request for proposals for 400 megawatts of renewable resources for Colorado Electric RAPID CITY, S.D. — Aug. 2, 2023 — Black Hills Corp. (NYSE: BKH) today announced financial results for the second quarter of 2023. Net income available for

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

As filed with the Securities and Exchange Commission on July 10, 2023 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 11-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 11-K x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 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 001-31303 A. Full title of the

Equity Distribution Sales Agreement dated June 16, 2023 among Black Hills Corporation and the several Agents named therein (filed as Exhibit 1.1 to the Registrant’s Form 8-K filed on June 20, 2023).

Exhibit 1.1 Black Hills Corporation Common Stock ($1.00 par value) EQUITY DISTRIBUTION SALES AGREEMENT June 16, 2023 BMO Capital Markets Corp. Bank of Montreal BofA Securities, Inc. Bank of America, N.A. MUFG Securities Americas Inc. MUFG Securities EMEA plc Mizuho Securities USA LLC Mizuho Markets Americas LLC RBC Capital Markets, LLC Royal Bank of Canada As Agents As Forward Purchasers Ladies an

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 16, 2023 Black Hills 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): June 16, 2023 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota 001-31303 46-0458824 (State or other jurisdiction of incorporation) (Commissi

As filed with the Securities and Exchange Commission on June 16, 2023

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on June 16, 2023 Registration No.

Statement of Eligibility and Qualification on Form T-1 of U.S. Bank Trust Company, National Association, Trustee (Subordinated Debt Securities).

Exhibit 25.2 securities and exchange commission Washington, D.C. 20549 FORM T-1 Statement of Eligibility Under The Trust Indenture Act of 1939 of a Corporation Designated to Act as Trustee Check if an Application to Determine Eligibility of a Trustee Pursuant to Section 305(b)(2) ¨ U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION (Exact name of Trustee as specified in its charter) 91-1821036 I.R.S. E

Calculation of Filing Fee Table Form S-3 (Form Type) Black Hills Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities

Exhibit 107 Calculation of Filing Fee Table Form S-3 (Form Type) Black Hills 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 Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid In Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid Equity Common stock, par value $1.

Filing Fee Table.

EX-FILING FEES 7 tm2318712d4exfiling-fees.htm EX-FILING FEES Exhibit 107 Calculation of Filing Fee Table Form S-3 (Form Type) Black Hills 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 Maximum

Statement of Eligibility and Qualification on Form T-1 of Computershare Trust Company, N.A., Trustee (Senior Debt Securities).

Exhibit 25.1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO SECTION 305(b)(2) ¨ Computershare Trust Company, National Association (Exact name of trustee as specified in its charter) N

Up to $400,000,000 Common Stock

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(5)  Registration Statement No. 333-272739 PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED JUNE 16, 2023 Up to $400,000,000 Common Stock We have entered into a sales agreement with BofA Securities, Inc., BMO Capital Markets Corp., Mizuho Securities USA LLC, MUFG Securities Americas Inc. and RBC Capital Markets, LLC, as our sales agents and as forward selle

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

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 14, 2023 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commissi

###

Black Hills Corp. Announces Key Executive Leadership Appointments RAPID CITY, S.D. – June 14, 2023 – Black Hills Corp. (NYSE: BKH) today announced changes within the company’s senior management team and appointed a new vice president and treasurer. Todd Jacobs is now senior vice president growth and strategy and Marne Jones is now senior vice president utilities, both effective June 15, 2023. Both

Letter Agreement between Black Hills Corporation and Jennifer C. Landis

Linden R. Evans President and CEO 7001 Mount Rushmore Road Rapid City, SD 57702 P: 605-721-2020 February 8th , 2023 HAND DELIVERED Jennifer Landis 7001 Mt. Rushmore Rd. Rapid City, South Dakota 57702 Dear Jenn: Per our discussions, you and Black Hills Corporation (“BHC”) have mutually agreed to amicably conclude your employment relationship with BHC. The purpose of this letter agreement (“Transiti

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

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

Table of Contents 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 001-31303 Bla

Three Months Ended March 31,

Black Hills Corp. Reports 2023 First-Quarter Results and Reaffirms 2023 Earnings Guidance • Issued request for proposals for 100 megawatts of utility-owned renewable resources for South Dakota Electric • Received approval for Colorado Clean Energy Plan and expect ownership of 200 megawatts of renewable resources • Strengthened balance sheet, liquidity and credit metrics • Sold Iowa wind assets for

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

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): April 24, 2023 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commiss

Amended and Restated Bylaws of Black Hills Corporation dated April 24, 2023.

AMENDED AND RESTATED BYLAWS OF BLACK HILLS CORPORATION ARTICLE I MEETINGS OF SHAREHOLDERS Section 1.

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

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): April 25, 2023 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commiss

ARS

2022 Annual Report | Proxy Statement | Form 10-K BLACK HILLS 2022 CORPORATIONWe are a customer focused, growth- oriented utility company with a tradition of exemplary service and a vision to be the energy partner of choice.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A 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 Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ 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)(2)) ☒ Defini

Eleventh Supplemental Indenture dated as of March 7, 2023 (filed as Exhibit 4.1 to the Registrant's Form 8-K filed on March 7, 2023).

Exhibit 4.1 BLACK HILLS CORPORATION AND COMPUTERSHARE TRUST COMPANY, N.A., AS TRUSTEE ELEVENTH SUPPLEMENTAL INDENTURE DATED AS OF MARCH 7, 2023 $350,000,000 5.950% NOTES DUE 2028 ELEVENTH SUPPLEMENTAL INDENTURE dated as of March 7, 2023 (this “Supplemental Indenture”), to the Indenture dated as of May 21, 2003 (the “Base Indenture” and, as supplemented by the First Supplemental Indenture dated as

Underwriting Agreement dated as of March 2, 2023 between Black Hills Corporation and the underwriters named therein.

Exhibit 1.1 Black Hills Corporation $350,000,000 5.950% Notes due 2028 UNDERWRITING AGREEMENT March 2, 2023 BofA Securities, Inc. One Bryant Park New York, New York 10036 J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 As Representatives (the “Representatives”) of the Several Underwriters Ladies and Gentlemen: 1. Introductory. Black Hills Corporation, a South Dakota corporat

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

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 02, 2023 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Commiss

PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED AUGUST 4, 2020 $350,000,000 5.950% Notes due 2028

TABLE OF CONTENTS   Filed Pursuant to Rule 424(b)(2)  Registration Statement No. 333-240320 PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED AUGUST 4, 2020 $350,000,000 5.950% Notes due 2028 Black Hills Corporation is offering $350,000,000 aggregate principal amount of 5.950% Notes due 2028 (the “Notes”). We will pay interest on the Notes on March 15 and September 15 of each year, beginning on September

Calculation of Filing Fee Table FORM S-3 (Form Type) BLACK HILLS CORPORATION (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities

EX-FILING FEES 2 tm237081d5exfilingfees.htm EX-FILING FEES Exhibit 107 Calculation of Filing Fee Table FORM S-3 (Form Type) BLACK HILLS 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 P

SUBJECT TO COMPLETION, DATED MARCH 2, 2023

TABLE OF CONTENTS The information in this preliminary prospectus supplement is not complete and may be changed.

Black Hills Corporation

Filed Pursuant to Rule 433 Registration No. 333-240320 Pricing Term Sheet March 2, 2023 Black Hills Corporation This communication should be read in conjunction with the preliminary prospectus supplement dated March 2, 2023 and the accompanying base prospectus. The information in this communication supersedes the information in the preliminary prospectus supplement and the accompanying base prospe

Black Hills Corporation Post-2018 Nonqualified Deferred Compensation Plan (filed as Exhibit 10.4 to the Registrant's Form 10-K for 2022).

Exhibit 10.4 Black Hills Corporation Amended & Restated Post-2018 Nonqualified Deferred Compensation Plan (Effective January 1, 2023) Content Copyright ©2018 Newport Group, Inc. All Rights Reserved. Black Hills Corporation Amended & Restated Post-2018 Nonqualified Deferred Compensation Plan Article I Establishment and Purpose 1 Article II Definitions 1 Article III Eligibility and Participation 8 A

Black Hills Corporation Amended and Restated 2015 Omnibus Incentive Plan effective Janaury 24, 2023.

Exhibit 10.6 Amended and Restated 2015 Omnibus Incentive Plan Black Hills Corporation (as amended and restated January 24, 2023) TABLE OF CONTENTS ARTICLE 1 ESTABLISHMENT, PURPOSE, AND DURATION 2 ARTICLE 2 DEFINITIONS 2 ARTICLE 3 ADMINISTRATION 6 ARTICLE 4 SHARES SUBJECT TO THIS PLAN AND MAXIMUM AWARDS 6 ARTICLE 5 ELIGIBILITY AND PARTICIPATION 8 ARTICLE 6 STOCK OPTIONS 8 ARTICLE 7 STOCK APPRECIATI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 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, 2022 ☐ TRANSITION REPORT PURSUANT TO SECTION

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 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, 2022 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 001-31303 BLACK HILLS CORPORATION Incorporated in South Dakota IRS Identification Number 46-0458824 7001 Mount Rushmore Road Rapid City, South Dakota 57702 Registrant’s telephone number (605) 721-1700 Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol Name of each exchange on which registered Common stock of $1.

Form of Short-term Incentive Plan Award Agreement for the Amended and Restated 2015 Omnibus Incentive Plan effective for awards granted on or after January 1, 2023.

Exhibit 10.28 Black Hills Corporation Short-Term Incentive Plan Award Agreement (Effective for Plan Years Beginning on or after January 1, 2023) You have been selected to be a Participant in the Black Hills Corporation Short-Term Incentive Plan (the “STIP”). The STIP is granted under the cash-based awards provisions of the Black Hills Corporation Amended and Restated 2015 Omnibus Incentive Plan (t

List of Subsidiaries of Black Hills Corporation.

Exhibit 21 BLACK HILLS CORPORATION SUBSIDIARIES December 31, 2022 Subsidiary Name State of Origin 1.

Change in Control Agreements dated November 15, 2022 between Black Hills Corporation and its non-CEO Senior Executive Officers.

Exhibit 10.18 CHANGE IN CONTROL AGREEMENT This Change in Control Agreement (“Agreement”) dated as of November 15, 2022, is entered into by and between Black Hills Corporation (“Company”) and (“Employee”). 1. RECITALS. The Board of Directors of the Company (“Board”) has determined that it is in the best interests of the Company and its shareholders to encourage the Employee’s full attention and ded

Mine Safety and Health Administration Safety Data

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

Form of Restricted Stock Award Agreement for the Amended and Restated 2015 Omnibus Incentive Plan effective for awards granted on or after January 24, 2023.

Exhibit 10.30 Black Hills Corporation Long-Term Incentive Plan Restricted Stock Award Agreement (Effective for Awards granted on or after January 24, 2023) You have been selected to be a Participant in the Black Hills Corporation Long-Term Incentive Plan (the “LTIP”). This LTIP award is granted under the restricted stock and restricted stock units provisions of the Amended and Restated 2015 Omnibu

Form of Performance Unit Award Agreement for the Amended and Restated 2015 Omnibus Incentive Plan effective for awards granted on or after January 1, 2023.

Exhibit 10.29 Black Hills Corporation Long-Term Incentive Plan Performance Unit Award Agreement Performance Period - January 1, 2023 – December 31, 2025 You have been selected to be a Participant in the Black Hills Corporation Long-Term Incentive Plan (the “LTIP”). This LTIP award is granted under the performance units and performance shares provisions of the Amended and Restated 2015 Omnibus Ince

Change in Control Agreement dated November 15, 2022 between Black Hills Corporation and Linden R. Evans.

Exhibit 10.17 CHANGE IN CONTROL AGREEMENT This Change in Control Agreement (“Agreement”) dated as of November 15, 2022, is entered into by and between Black Hills Corporation (“Company”) and Linden R. Evans (“Employee”). 1. RECITALS. The Board of Directors of the Company (“Board”) has determined that it is in the best interests of the Company and its shareholders to encourage the Employee’s full a

BKH / Black Hills Corp / STATE STREET CORP Passive Investment

SC 13G/A 1 BlackHillsCorp.txt UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 AMEMDED FILING BLACK HILLS CORP (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 092113109 (CUSIP NUMBER) 12/31/2022 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT T

BKH / Black Hills Corp / 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.: 12)* Name of issuer: Black Hills Corp. Title of Class of Securities: Common Stock CUSIP Number: 092113109 Date of Event Which Requires Filing of this Statement: December 30, 2022 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ 

Three Months Ended Dec. 31,

EX-99 2 bkh-ex99.htm EARNINGS RELEASE Black Hills Corp. Reports 2022 Fourth-Quarter and Full-Year Results and Revises 2023 Earnings Guidance • New winter peak loads recorded at all three electric utilities in December • 2023 to 2027 capital investment forecast of $3.5 billion • Revised 2023 EPS guidance range of $3.65 to $3.85 • Long-term EPS growth target of 4% to 6% off 2023 base RAPID CITY, S.D

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 07, 2023 Black Hills Corporation (Exact name of Registrant as Specified in Its Charter) South Dakota 001-31303 46-0458824 (State or Other Jurisdiction of Incorporation) (Comm

BKH / Black Hills Corp / BlackRock Inc. Passive Investment

SC 13G/A 1 us0921131092012623.txt us0921131092012623.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 14) BLACK HILLS CORPORATION - (Name of Issuer) Common Stock - (Title of Class of Securities) 092113109 - (CUSIP Number) December 31, 2022 - (Date of Event Which Requires Filing of this Statement) Check the appropria

BKH / Black Hills Corp / BlackRock Inc. Passive Investment

SC 13G/A 1 us0921131092011923.txt us0921131092011923.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 13) BLACK HILLS CORPORATION - (Name of Issuer) Common Stock - (Title of Class of Securities) 092113109 - (CUSIP Number) December 31, 2022 - (Date of Event Which Requires Filing of this Statement) Check the appropria

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

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, 2022 ☐ TRANSITION REPORT PURSUANT

Table of Contents 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, 2022 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 001-313

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 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) November 2, 2022 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 (Commission File N

BLACK HILLS CORPORATION CONSOLIDATED FINANCIAL RESULTS (Minor differences may result due to rounding) Three Months Ended Sept. 30, Nine Months Ended Sept. 30, 2022 2021 2022 2021 (in millions) Operating income: Electric Utilities (a) (b) $ 69.5 $ 72.

Black Hills Corp. Reports Third Quarter 2022 Results and Reaffirms Earnings Guidance ?2022 EPS guidance range of $3.95 to $4.15 reaffirmed ?2023 EPS guidance range of $4.00 to $4.20 initiated ?2022 to 2026 capital investment forecast increased $250 million to $3.5 billion ?Ready Wyoming transmission expansion project approved ?Quarterly dividend increased 5% ?Net Zero by 2035 target for natural ga

Black Hills Corp. Announces CFO Retirement and Leadership Appointment

Black Hills Corp. Announces CFO Retirement and Leadership Appointment RAPID CITY, S.D. — Oct. 27, 2022 — Black Hills Corp. (NYSE: BKH) today announced that Richard Kinzley, senior vice president and chief financial officer, will retire from the Company in mid-2023 after a distinguished career with the company. Consistent with the company’s long-standing and comprehensive leadership succession plan

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) October 27, 2022 Black Hills Corpo

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) October 27, 2022 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 (Commission File N

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, 2022 ☐ TRANSITION REPORT PURSUANT TO S

Table of Contents 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, 2022 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 001-31303 Bl

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

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 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) August 3, 2022 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 (Commission File Num

BLACK HILLS CORPORATION CONSOLIDATED FINANCIAL RESULTS (Minor differences may result due to rounding) Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 (in millions) Operating income: Electric Utilities (a) (b) (c) $ 45.2 $ 47

Black Hills Corp. Reports Second Quarter 2022 Results and Reaffirms Earnings Guidance RAPID CITY, S.D. ? August 3, 2022 ? Black Hills Corp. (NYSE: BKH) today announced financial results for the second quarter of 2022. Net income for the three and six months ended June 30, 2022, compared to the three and six months ended June 30, 2021, was: Three Months Ended June 30, Six Months Ended June 30, 2022

BKH / Black Hills Corp / STATE STREET CORP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 AMENDED FILING BLACK HILLS CORP (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 092113109 (CUSIP NUMBER) 06/30/2022 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT TO WHICH THIS SCHEDULE IS FILED

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 11-K x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR o TRANSITION REPORT PURSUANT TO SECTION

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 11-K x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 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 001-31303 A. Full title of the

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

As filed with the Securities and Exchange Commission on May 5, 2022

As filed with the Securities and Exchange Commission on May 5, 2022 Registration No.

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) Black Hills Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered(1) Proposed Maximum Offering Price Per Unit(2) Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Equity Common Stock, par value $1.

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, 2022 ☐ TRANSITION REPORT PURSUANT TO

Table of Contents 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, 2022 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 001-31303 B

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 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) May 4, 2022 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 (Commission File Number

BLACK HILLS CORPORATION CONSOLIDATED FINANCIAL RESULTS (Minor differences may result due to rounding) Three Months Ended March 31, 2022 2021 (in millions) Operating income: Electric Utilities (a) (b) (c) $ 50.7 $ 39.3 Gas Utilities (c) 123.5 102.1 Co

EX-99 2 ex-99q12022earningsrelease.htm EX-99 Black Hills Corp. Reports Strong First Quarter 2022 Results and Reaffirms Earnings Guidance RAPID CITY, S.D. — May 4, 2022 — Black Hills Corp. (NYSE: BKH) today announced financial results for the first quarter of 2022. Net income for the first quarter of 2022 compared to the first quarter of 2021 was: Three Months Ended March 31, 2022 2021 (in millions

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 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) April 26, 2022 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 (Commission File Num

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A 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 Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ? 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)(2)) ? Defin

Mine Safety and Health Administration Safety Data

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

List of Subsidiaries of Black Hills Corporation.

Exhibit 21 BLACK HILLS CORPORATION SUBSIDIARIES December 31, 2021 Subsidiary Name State of Origin 1.

Form of Restricted Stock Unit Award Agreement (Non-Employee Director) effective for awards granted on or after January 1, 2022 (filed as Exhibit 10.26 to the Registrant's Form 10-K filed on February 15, 2022).

BLACK HILLS CORPORATION NON-EMPLOYEE DIRECTOR EQUITY COMPENSATION PLAN UNDER THE BLACK HILLS CORPORATION AMENDED AND RESTATED 2015 omnibus INCENTIVE PLAN Restricted Stock Unit Award Agreement (Non-Employee Director) Black Hills Corporation (the ?Company?), pursuant to its Non-Employee Director Equity Compensation Plan (the ?Non-Employee Director Equity Plan?) under its Amended and Restated 2015 Omnibus Incentive Plan (the ?Omnibus Plan?), hereby grants an award of Restricted Stock Units to you, the Participant named below.

Non-Employee Director Equity Compensation Plan effective January 1, 2022.

BLACK HILLS CORPORATION NON-EMPLOYEE DIRECTOR EQUITY Compensation Plan (Effective January 1, 2022) Article 1 - Purpose 1.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 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, 2021 ☐ TRANSITION REPORT PURSUANT TO SECTION

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 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, 2021 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 001-31303 BLACK HILLS CORPORATION Incorporated in South Dakota IRS Identification Number 46-0458824 7001 Mount Rushmore Road Rapid City, South Dakota 57702 Registrant?s telephone number (605) 721-1700 Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol Name of each exchange on which registered Common stock of $1.

BKH / Black Hills Corp / STATE STREET CORP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 AMENDED FILING BLACK HILLS CORP (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 092113109 (CUSIP NUMBER) 12/31/2021 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT TO WHICH THIS SCHEDULE IS FILED

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 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) February 9, 2022 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 (Commission File N

BLACK HILLS CORPORATION CONSOLIDATED FINANCIAL RESULTS (Unaudited) (Minor differences may result due to rounding) Three Months Ended Dec. 31, Twelve Months Ended Dec. 31, 2021 2020 2021 2020 (in millions) Operating income: Electric Utilities (a) $ 43

Black Hills Corp. Reports 2021 Fourth Quarter and Full Year Results and Reaffirms 2022 Guidance RAPID CITY, S.D. ? Feb. 9, 2022 ? Black Hills Corp. (NYSE: BKH) today announced financial results for the fourth quarter and full year ended Dec. 31, 2021. Net income and net income, as adjusted (non-GAAP) for the fourth quarter and full year 2021 compared to the fourth quarter and full year 2020 were:

BKH / Black Hills Corp / 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.: 11)* Name of issuer: Black Hills Corp. Title of Class of Securities: Common Stock CUSIP Number: 092113109 Date of Event Which Requires Filing of this Statement: December 31, 2021 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ 

BKH / Black Hills Corp / BlackRock Inc. Passive Investment

us0921131092012822.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 12) BLACK HILLS CORPORATION - (Name of Issuer) Common Stock - (Title of Class of Securities) 092113109 - (CUSIP Number) December 31, 2021 - (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursu

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, 2021 ☐ TRANSITION REPORT PURSUANT

Table of Contents 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, 2021 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 001-313

Mine Safety and Health Administration Safety Data.

Exhibit 95 Information concerning mine safety violations or other regulatory matters required by Sections 1503(a) of Dodd-Frank is included below.

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 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) November 2, 2021 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 (Commission File N

BLACK HILLS CORPORATION CONSOLIDATED FINANCIAL RESULTS (Minor differences may result due to rounding) Three Months Ended Sept. 30, Nine Months Ended Sept. 30, 2021 2020 2021 2020 (in millions) Adjusted operating income (a): Electric Utilities (b) $ 5

Black Hills Corp. Reports Third Quarter 2021 Results and Raises Midpoint of 2021 EPS Guidance ?Raises lower end of 2021 EPS guidance range and reaffirms 2022 EPS guidance ?Ready Wyoming electric transmission expansion initiative announced ?2021 to 2025 capital investment forecast increased by $149 million to $3.2 billion ?Quarterly dividend increased by 5.3%, achieving 51 consecutive years of annu

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) September 15, 2021 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 (Commission File

Tenth Supplemental Indenture dated as of August 26, 2021 (filed as Exhibit 4.1 to the Registrant’s Form 8-K filed on August 26, 2021).

Exhibit 4.1 BLACK HILLS CORPORATION AND WELLS FARGO BANK, NATIONAL ASSOCIATION AS TRUSTEE TENTH SUPPLEMENTAL INDENTURE DATED AS OF AugusT 26, 2021 $600,000,000 1.037% NOTES DUE 2024 TENTH SUPPLEMENTAL INDENTURE dated as of August 26, 2021 (this ?Supplemental Indenture?), to the Indenture dated as of May 21, 2003 (the ?Base Indenture? and, as supplemented by the First Supplemental Indenture dated a

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): August 23, 2021 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota 001-31303 46-0458824 (State or other jurisdiction of incorporation) (Commis