BKH / Black Hills Corporation - Pengajuan SECLaporan Tahunan, Pernyataan Proksi

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 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

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 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.

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.

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 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.

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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

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

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

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 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

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

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

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

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.

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

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.

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

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

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.

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

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 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

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

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): 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

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

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.

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

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

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.

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, 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

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

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

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

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

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

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

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

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

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

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.

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.

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

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

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

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

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

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

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”).

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.

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, 2023 Subsidiary Name State of Origin 1.

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.

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”).

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

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

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

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

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): 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

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

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

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

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

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.

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.

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

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.

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.

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

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.

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

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

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

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

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

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

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.

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

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.

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

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

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.

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

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

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 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

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

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

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

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

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

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

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 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

List of Subsidiaries of Black Hills Corporation.

Exhibit 21 BLACK HILLS CORPORATION SUBSIDIARIES December 31, 2022 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.

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

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

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

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

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

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

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

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

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.

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

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

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

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 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

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

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

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) 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

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.

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.

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

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: ☒ 

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:

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.

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

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

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

Underwriting Agreement dated as of August 23, 2021 between Black Hills Corporation and the underwriters named therein.

Exhibit 1.1 Black Hills Corporation $600,000,000 1.037% Notes due 2024 UNDERWRITING AGREEMENT August 23, 2021 U.S. Bancorp Investments, Inc. 214 N. Tryon St., 26th Floor Charlotte, NC 28202 BMO Capital Markets Corp. 3 Times Square, 25th Floor New York, New York 10036 Wells Fargo Securities, LLC 550 South Tryon Street ? 5th Floor Charlotte, North Carolina 28202 As Representatives (the ?Representati

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

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

CALCULATION OF REGISTRATION FEE

TABLE OF CONTENTS ?Filed Pursuant to Rule 424(b)(2)? ?Registration Statement No. 333-240320? CALCULATION OF REGISTRATION FEE ? ? Title of Each Class of Securities To Be Registered ? ? ? Amount To Be Registered ? ? ? Proposed Maximum Offering Price Per Unit ? ? ? Proposed Maximum Aggregate Offering Price ? ? ? Amount of Registration Fee(1) ? 1.037% Notes due 2024 ? ? ? $600,000,000 ? ? ? 100.000% ?

Black Hills Corporation

Filed Pursuant to Rule 433 Registration No. 333-240320 Pricing Term Sheet August 23, 2021 Black Hills Corporation This communication should be read in conjunction with the preliminary prospectus supplement dated August 23, 2021 and the accompanying base prospectus. The information in this communication supersedes the information in the preliminary prospectus supplement and the accompanying base pr

SUBJECT TO COMPLETION, DATED AUGUST 23, 2021

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 June 30, 2021 ☐ 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, 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 Bl

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, 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 Num

BLACK HILLS CORPORATION CONSOLIDATED FINANCIAL RESULTS (Minor differences may result due to rounding) Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (in millions) Adjusted operating income (a): Electric Utilities (b) $ 35.6

Black Hills Corp. Reports Second Quarter 2021 Results and Reaffirms Guidance RAPID CITY, S.D. ? Aug. 3, 2021 ? Black Hills Corp. (NYSE: BKH) today announced financial results for the second quarter of 2021. Net income and Net income, as adjusted (non-GAAP) for the second quarter and first six months of 2021 compared to the second quarter and first six months of 2020 were: Three Months Ended June 3

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 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) July 19, 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 Numb

Fourth Amended and Restated Credit Agreement dated as of July 19, 2021 (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 (filed as Exhibit 10.1 to the Registrant’s Form 8-K filed on July 19, 2021).

EXECUTION VERSION Deal CUSIP 09211MAG2 Revolving Facility CUSIP 09211MAH0 FOURTH AMENDED AND RESTATED CREDIT AGREEMENT DATED AS OF July 19, 2021 AMONG BLACK HILLS CORPORATION, as the Borrower, THE FINANCIAL INSTITUTIONS PARTY HERETO, as Banks, U.

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, 2020 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, 2020 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.

Quarterly Report - 10-Q

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, 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 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, 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 Number

BLACK HILLS CORPORATION CONSOLIDATED FINANCIAL RESULTS (Minor differences may result due to rounding) Three Months Ended March 31, 2021 2020 (in millions) Adjusted operating income (a): Electric Utilities (b) (c) $ 21.8 $ 35.7 Gas Utilities 102.1 102

Black Hills Corp. Reports First Quarter 2021 Results and Reaffirms Guidance RAPID CITY, S.D. ? May 4, 2021 ? Black Hills Corp. (NYSE: BKH) today announced financial results for the first quarter of 2021. Net income and Net income, as adjusted (non-GAAP) for the first quarter of 2021 compared to the first quarter of 2020 were: Three Months Ended March 31, 2021 2020 (in millions, except per share am

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 27, 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 Num

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/A 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 16, 2020 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 (Commission Fi

- DEF 14A

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 x 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)) x Defin

Form of Restricted Stock Award Agreement for 2015 Omnibus Incentive Plan effective for awards granted on or after January 26, 2021. (filed as Exhibit 10.11 to the Registrant's Form 10-K for 2020)

Black Hills Corporation 2015 Omnibus Incentive Plan Restricted Stock Award Agreement (Effective for Awards granted on or after January 26, 2021) Dear : Congratulations on your selection as a Participant under Black Hills Corporation?s 2015 Omnibus Incentive Plan (the ?Plan?).

Form of Performance Unit Award Agreement for 2015 Omnibus Incentive Plan effective for awards granted on or after January 1, 2021. (filed as Exhibit 10.17 to the Registrant's Form 10-K for 2020)

Black Hills Corporation 2015 Omnibus Incentive Plan Performance Unit Award Agreement (for Awards granted on or after January 1, 2021) Performance Period - January 1, 2021 ? December 31, 2023 Contents Article 1.

Black Hills Corporation Amended and Restated 2015 Omnibus Incentive Plan effective January 26, 2021.

Amended and Restated 2015 Omnibus Incentive Plan Black Hills Corporation Effective January 26, 2021 Table of Contents Article 1.

Form of Short-term Incentive Plan for Officers Award Agreement effective for awards granted on or after January 1, 2021 (filed as Exhibit 10.16 to the Registrant's Form 10-K for 2020).

Black Hills Corporation Short- Term Incentive Plan for Officers Award Agreement (Effective for Plan Years Beginning on or after January 1, 2021) Contents Article 1 Effective Date and Purpose of Plan 1 Article 2 Definitions 1 Article 3 Eligibility and Participants 2 Article 4 Administration of the Plan 2 Article 5 Target Incentive Award and Performance Measures 2 Article 6 Termination Provisions 3

Annual Report - 10-K

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, 2020 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.

List of Subsidiaries of Black Hills Corporation.

Exhibit 21 BLACK HILLS CORPORATION SUBSIDIARIES December 31, 2020 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.

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 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) February 24, 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

Credit Agreement dated as of February 24, 2021 among Black Hills Corporation, as Borrower, the financial institutions party thereto, as Banks, and U.S. Bank National Association, as Administrative Agent (filed as Exhibit 10.1 to the Registrant’s Form 8–K filed on February 25, 2021).

EXECUTION VERSION Deal CUSIP 09211MAJ6 Term Facility CUSIP 09211MAK3 CREDIT AGREEMENT DATED AS OF February 24, 2021 AMONG BLACK HILLS CORPORATION, as the Borrower, THE FINANCIAL INSTITUTIONS PARTY HERETO, as Banks, and U.

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 10)*

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 10)* 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, 2020 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ 

BLACK HILLS CORPORATION CONSOLIDATED FINANCIAL RESULTS (Unaudited) (Minor differences may result due to rounding) Three Months Ended Dec. 31, Twelve Months Ended Dec. 31, 2020 2019 2020 2019 (in millions) Adjusted operating income (a) : Electric Util

Black Hills Corp. Reports Strong 2020 Fourth Quarter and Full Year Results and Provides Five-year Growth Outlook •Reports 2020 GAAP EPS of $3.65 and EPS of $3.73, as adjusted •Increases 2021 guidance to $3.80 to $4.00 per share •Initiates 2022 guidance of $3.95 to $4.15 per share •Targets 5% to 7% long-term EPS growth rate •Increases expected five-year capital investment to $3.0+ billion RAPID CIT

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, 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

SCHEDULE 13G

SC 13G/A 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1 )* Black Hills Corporation (Name of Issuer) Common Stock (Title of Class of Securities) 092113109 (CUSIP Number) December 31, 2020 (Date of Event Which Requires Filing of this Statement) Check the appropriate bo

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.

Quarterly Report - 10-Q

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, 2020 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

2020 Earnings Guidance Reconciliation LOW HIGH Earnings per share (GAAP) $ 3.52 $ 3.62 Adjustments**: Impairment of investment 0.11 0.11 Tax on Adjustments**: Impairment of investment (0.03) (0.03) Total adjustments 0.08 0.08 Earnings per share, as a

Black Hills Corp. Reports Strong Third Quarter 2020 Results and Provides Guidance Update Increases 2020 Earnings Guidance to $3.60 to $3.70 Per Share and Introduces 2021 Guidance •Reports third quarter EPS of $0.58; strong growth compared to the third quarter of 2019 •Increases 2020 EPS guidance range to $3.60 to $3.70 from $3.45 to $3.65 •Initiates 2021 EPS guidance range of $3.75 to $3.95 •Incre

Financial Statements and Exhibits, Results of Operations and Financial Condition - 8-K

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, 2020 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

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits - 8-K

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 16, 2020 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 (Commission File

Black Hills Corp. Announces Two New Appointments to Board of Directors

Black Hills Corp. Announces Two New Appointments to Board of Directors Rapid City, S.D. – Sept. 18, 2020 – Black Hills Corp. (NYSE: BKH) today announced the appointment of Barry M. Granger and Scott M. Prochazka to its board of directors, effective Oct. 1, 2020. In anticipation of future retirements, the board also temporarily increased the size of the board from 10 to 12 directors. “We are please

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): August 4, 2020 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

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, 2020 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

CALCULATION OF REGISTRATION FEE

TABLE OF CONTENTS Filed Pursuant to Rule 424(b)(5) Registration No. 333-240320 CALCULATION OF REGISTRATION FEE Title Of Each Class Of Securities To Be Registered Maximum Aggregate Offering Price(1)(2) Amount Of Registration Fee(2)(3) Common stock, par value $1.00 $ 400,000,000.00 $ 25,960.00 (1) Pursuant to Rule 416 under the Securities Act, the number of shares being registered shall be adjusted

2020 Earnings Guidance Reconciliation LOW HIGH Earnings per share (GAAP) $ 3.37 $ 3.57 Adjustments**: Impairment of investment 0.11 0.11 Tax on Adjustments**: Impairment of investment (0.03) (0.03) Total adjustments 0.08 0.08 Earnings per share, as a

Black Hills Corp. Reports Second Quarter 2020 Results and Reaffirms Earnings Guidance •Reported earnings per share of $0.33, up from $0.24 per share in second quarter of 2019 •Capital plan of $669 million for 2020 on schedule •Enhanced strong liquidity position with $400 million debt issuance leading to $770 million of liquidity at quarter-end •Expense management offsets COVID-19 expenses RAPID CI

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

EX-25.2 7 tm2026272d2ex25-2.htm FORM T-1 (SUBORDINATED TRUSTEE) Exhibit 25.2 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) U.S. BANK NATIONAL ASSOCIATION (Exact nam

CALCULATION OF REGISTRATION FEE

TABLE OF CONTENTS Filed Pursuant to Rule 424(b)(5) Registration No. 333-240320 CALCULATION OF REGISTRATION FEE Title Of Each Class Of Securities To Be Registered Maximum Aggregate Offering Price(1)(2) Amount Of Registration Fee(2)(3) Common stock, par value $1.00 $ 400,000,000.00 $ 25,960.00 (1) Pursuant to Rule 416 under the Securities Act, the number of shares being registered shall be adjusted

Quarterly Report - 10-Q

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, 2020 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

- S-3ASR

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on August 4, 2020 Registration No.

Statement of Eligibility and Qualification on Form T-1 of Wells Fargo Bank, National Association, 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) WELLS FARGO BANK, NATIONAL ASSOCIATION (Exact name of trustee as specified in its charter) A National

Power of Attorney.

Exhibit 24.1 POWER OF ATTORNEY Each of the undersigned officers and directors of Black Hills Corporation, a South Dakota corporation, hereby constitutes and appoints Linden R. Evans and Brian G. Iverson, and each of them, as his or her true and lawful attorney-in-fact and agent, severally, with full power of substitution and resubstitution, in his or her name and on his or her behalf, in any and a

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.

Power of Attorney.

Exhibit 24 POWER OF ATTORNEY Each of the undersigned officers and directors of Black Hills Corporation, a South Dakota corporation, hereby constitutes and appoints Linden R.

Equity Distribution Sales Agreement dated August 4, 2020 among Black Hills Corporation and the several Agents named therein (filed as Exhibit 1.1 to the Registrant’s Form 8-K filed on August 4, 2020).

Exhibit 1.1 Black Hills Corporation Common Stock ($1.00 par value) EQUITY DISTRIBUTION SALES AGREEMENT August 4, 2020 MUFG Securities Americas Inc. MUFG Securities EMEA plc BofA Securities, Inc. Bank of America, N.A. Credit Suisse Securities (USA) LLC Credit Suisse Capital LLC Morgan Stanley & Co. LLC Morgan Stanley & Co. LLC c/o MUFG Securities Americas Inc. c/o MUFG Securities EMEA plc 1221 Aven

- UNIVERSAL SHELF REGISTRATION STATEMENT

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on August 4, 2020 Registration No.

- 11-K

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, 2019 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 plan and the addr

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): June 12, 2020 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

Underwriting Agreement dated as of June 12, 2020 between Black Hills Corporation and the underwriters named therein.

Exhibit 1.1 Black Hills Corporation $400,000,000 2.500% Notes due 2030 UNDERWRITING AGREEMENT June 12, 2020 Wells Fargo Securities, LLC 550 South Tryon Street – 5th Floor Charlotte, North Carolina 28202 J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 RBC Capital Markets, LLC Brookfield Place 200 Vesey Street, 8th Floor New York, New York 10281 As Representatives (the “Repres

Ninth Supplemental Indenture dated as of June 17, 2020 (filed as Exhibit 4.1 to the Registrant’s Form 8-K filed on June 17, 2020).

Exhibit 4.1 BLACK HILLS CORPORATION AND WELLS FARGO BANK, NATIONAL ASSOCIATION AS TRUSTEE NINTH SUPPLEMENTAL INDENTURE DATED AS OF JUNE 17, 2020 $400,000,000 2.500% NOTES DUE 2030 NINTH SUPPLEMENTAL INDENTURE dated as of June 17, 2020 (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 of

CALCULATION OF REGISTRATION FEE Title of Each Class of Securities To Be Registered Amount To Be Registered Proposed Maximum Offering Price Per Unit Proposed Maximum Aggregate Offering Price Amount of Registration Fee(1) 2.500% Notes due 2030 $400,000

Use these links to rapidly review the document TABLE OF CONTENTS TABLE OF CONTENTS Table of Contents Filed Pursuant to Rule 424(b)(2) Registration Statement No.

SUBJECT TO COMPLETION, DATED JUNE 12, 2020 PRELIMINARY PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED AUGUST 4, 2017 $ % Notes due 20

Use these links to rapidly review the document TABLE OF CONTENTS TABLE OF CONTENTS Table of Contents Filed pursuant to Rule 424(b)(5) Registration Statement No.

Black Hills Corporation

Filed Pursuant to Rule 433 Registration No. 333-219705 Pricing Term Sheet June 12, 2020 Black Hills Corporation This communication should be read in conjunction with the preliminary prospectus supplement dated June 12, 2020 and the accompanying base prospectus. The information in this communication supersedes the information in the preliminary prospectus supplement and the accompanying base prospe

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.

Quarterly Report - 10-Q

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, 2020 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

Preferability letter from Deloitte & Touche LLP regarding change in pension accounting asset method.

May 5, 2020 Black Hills Corporation 7001 Mount Rushmore Road Rapid City, South Dakota 57702 Dear Sirs/Madams: At your request, we have read the description included in your Quarterly Report on Form 10-Q for Black Hills Corporation and its subsidiaries (the Company) to the Securities and Exchange Commission for the quarter ended March 31, 2020, of the facts relating to the Company’s election to change its principle of accounting for defined benefit pension costs.

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, 2020 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

Three Months Ended March 31,

Black Hills Corp. Reports First Quarter 2020 Results and Revises Guidance • Black Hills continues to safely and reliably deliver energy for customers during COVID-19 pandemic challenges • Minimal financial impacts from COVID-19 in the first quarter • Strong liquidity to fund operations and capital plan RAPID CITY, S.D. — May 4, 2020 — Black Hills Corp. (NYSE: BKH) today announced financial results

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/A 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 29, 2019 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 (Commission File

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 28, 2020 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

BKH / Black Hills Corp. DEFA14A - - DEFA14A

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 x 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

definitive proxy statement for the Company’s 2020 Annual Meeting of Shareholders filed on March 13, 2020

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 x 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)) x Defin

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) March 9, 2020 Black Hills Corporation (Exact name of registrant as specified in its charter) South Dakota (State or other jurisdiction of incorporation) 001-31303 46-0458824 (Commissio

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 24, 2020 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

Underwriting Agreement dated February 24, 2020 between Black Hills Corporation and BMO Capital Markets Corp.

Exhibit 1.1 Black Hills Corporation 1,222,942 Shares of Common Stock, Par Value $1.00 Per Share UNDERWRITING AGREEMENT February 24, 2020 BMO Capital Markets Corp. 3 Times Square, 25th Floor New York, New York 10036 Ladies and Gentlemen: 1. Introductory. Black Hills Corporation, a South Dakota corporation (the “Company”), agrees with BMO Capital Markets Corp. (the “Underwriter”) to issue and sell t