BLACK HILLS COMMUNITY BANK, N.A.

tainment of age 65, total and permanent disability, or death. Contributions — Contributions to the Plan include (i) salary reduction contributions authorized by participants, (ii) matching contributions made by the Company, (iii) non-elective contributions made by the Company; and (iv) participant rollovers from another plan. Participants may contribute up to 50 % of th eir eligible compensation to the Plan each year. These contributions are subject to certain IRC limitations with an annual maximum pre-tax contribution of $ 23,500 for 2025 and $ 23,000 for 2024. Combined employee pre-tax, employee after-tax, employee Roth and employer contributions per participant (excluding catch-up contributions) were limited to the lesser of $ 70,000 and $ 69,000 in 2025 and 2024, respectively or 50 % o

contribution portion of their accounts is based on years of service at a rate of 20 % per year. A participant is 100 % vested after five years of service. Participants also become fully vested in Company contributions if their employment with the Company is terminated due to retirement at or after attainment of age 65, total and permanent disability, or death. Contributions — Contributions to the Plan include (i) salary reduction contributions authorized by participants, (ii) matching contributions made by the Company, (iii) non-elective contributions made by the Company; and (iv) participant rollovers from another plan. Participants may contribute up to 50 % of th eir eligible compensation to the Plan each year. These contributions are subject to certain IRC limitations with an annual max

nd Vesting — Employees meeting certain criteria, as defined in the Plan, are eligible to participate in the Plan one month following their date of employment. The Plan includes an automatic enrollment provision whereby all newly eligible employees are automatically enrolled in the Plan unless they affirmatively elect not to participate in the Plan. Automatically enrolled participants have their deferral rate se t at 6 % of eligible compensation and their contributions are invested in a target retirement fund appropriate for their age until changed by the participant. The Plan includes an Automatic Savings Increase (ASI) feature where the participant’s savings rate will increase 1 % annually until their savings rate reaches 15 %, they have el ected to change their savings rate, or they have

ome 135,987,945   Other income:  Interest received on notes receivable from participants 833,025   Total additions to net assets 203,141,397   Deductions from net assets:  Administrative expenses ( 198,018 ) Benefits paid to participants ( 80,429,078 ) Total deductions from net assets ( 80,627,096 )  Increase in net assets available for benefits 122,514,301   Net assets available for benefits:  Beginning of year 811,221,284 End of year $ 933,735,585 See Notes to Financial Statements . 5 Table of Contents BLACK HILLS CORPORATION 401(k) RETIREMENT SAVINGS PLAN NOTES TO FINANCIAL STATEMENTS As of December 31, 2025 and 2024 and for the Year Ended December 31, 2025 (1) DESCRIPTION OF THE PLAN The following description of the Black Hills Corporation 401(k) Retirement Savings Plan (th

ued under the Plan cannot exceed 400,000 shares of common stock. Shares available for issuance at February 28, 2026 were 188,269 . Certent, Inc. is the record keeper for the Plan. Administrative expenses of the Plan are paid by the Company. Plan Year The Plan year begins on March 1 and ends on February 28 (or February 29 in the case of a leap year). ​ Eligibility An employee of the Company or any Participating Subsidiary is eligible to participate in the Plan if the employee has been continuously employed by the Company or any Participating Subsidiary for at least 90 days (except that any bona fide leave of absence will not render a participant so long as the leave does not exceed three months or, if longer than three months, the individual’s right to reemployment is provided by statute or

llows employees to make contributions to the 401(k) Plan and United matches 100 % of employee deferral contributions up to 5 % of eligible compensation. Employees begin to receive matching contributions after completing 90 days of service. Under safe harbor provisions, United is required to provide a matching contribution and participants are immediately 100% vested in safe harbor matching contributions. United’s 401(k) Plan is administered in accordance with applicable laws and regulations. Compensation expense related to the 401(k) Plan totaled $ 11.6 million, $ 11.2 million and $ 10.9 million in 2025, 2024 and 2023, respectively. Deferred Compensation Plan United also sponsors a non-qualified deferred compensation plan for its executive officers, certain other key employees and members

ed-average period of 2.6 years. Options granted or assumed in 2023 were related to the Progress acquisition, with the weighted average exercise price of the acquired institution’s fully vested converted options determined pursuant to the purchase agreement. The value of the options was determined using a Black-Scholes model and was included in the acquisition’s purchase price. No compensation expense relating to options was included in earnings for 2025, 2024 or 2023. All outstanding options were vested and exercisable at December 31, 2025. (17) Reclassifications Out of AOCI The following presents the details regarding amounts reclassified out of AOCI . Amounts shown above in parentheses reduce earnings. (in thousands) Amounts Reclassified from AOCI For the Years Ended December 31, Details

minal pleas. Our Board has approved policies and procedures that it believes comply with these laws. Depositor Preference Federal law provides that deposits and certain claims for administrative expenses and associate compensation against an insured depository institution would be afforded a priority over other general unsecured claims against such an institution, including federal funds and letters of credit, in the “liquidation or other resolution” of such an institution by any receiver. Insurance Activities Certain of our subsidiaries sell various types of insurance as agent in a number of states. Insurance activities are subject to regulation by the states in which such business is transacted. Although most of such regulation focuses on insurance companies and their insurance products,