The terms and conditions pursuant to which an Option vests in the Participant and becomes exercisable shall be determined by the Administrator and set forth in the applicable Award Agreement. Such vesting may be based on service with the Company or any Affiliate, any of the Performance Criteria, or any other criteria selected by the Administrator. At any time after the grant of an Option, the Administrator may, in its sole discretion and subject to whatever terms and conditions it selects, accelerate the vesting of the Option.

-4 Vesting Notwithstanding anything in Section 4.2 to the contrary, [Schedule D.1] Participants shall be vested in their Retirement Contribution Accounts upon completing three years of Vesting Service. For this purpose, a “Year of Vesting Service” means a Plan Year in which the [Schedule D.1] Participant is credited with at least 1,000 Hours of Service. Service with Knife River Corporation and Affiliates shall be recognized for purposes of this Section D.1-4, including, but not limited to, service that occurred prior to the Effective Date, applying these rules as if Knife River Corporation and its affiliates at that time were Affiliates under the Plan. Notwithstanding the foregoing, a [Schedule D.1] Participant shall be fully vested in his or her Retirement Contribution Account upon death, Disability, or attaining Normal Retirement Age.

Vesting Conditions. Your Incentive Bonus will be subject to repayment in accordance with the provisions of this Section 2.

General Vesting. Except as otherwise provided in [Sections 3(b) and 4] below, your Award shall vest on <> (the “Vesting Date”) if you remain a member of the Board of Directors of ​ or one of its Subsidiaries continuously through the Vesting Date.

Vesting Acceleration. Effective as of January 1, 2019, # Gulf Power Company will cease to be an Employing Company under the Plan; and # Participants who cease to be Employees due to the sale of Gulf Power Company will be deemed to be fully vested in their Accounts for all purposes hereunder.

Scheduled Vesting. The number of Units that have been earned during the Performance Period, as determined by the Committee in accordance with [Exhibit 1], will vest on the Scheduled Vesting Date, so long as your Service has been continuous from the Grant Date to the Scheduled Vesting Date. For these purposes, the “Scheduled Vesting Date” means the date the Committee certifies # the degree to which

Scheduled Vesting. If you remain a member of the Board continuously from the Grant Date specified on the cover page of this Agreement, then the Units will vest in the numbers and on the dates specified in the Vesting Schedule on the cover page of this Agreement.

Accelerated Vesting. The vesting of outstanding Units will be accelerated under the circumstances provided below:

Vesting Schedule. Except as provided in [Section 5], and subject to [Section 6], the Shares subject to this Award will vest in accordance with the vesting provisions set forth in the Notice of Grant of Restricted Stock Award and Exhibit A. Shares subject to this Award scheduled to vest on a certain date or upon the occurrence of a certain condition will not vest in accordance with any of the provisions of this RSA Agreement and Exhibit A, unless Participant has continuously satisfied the Service Condition from the Grant Date until the date such vesting occurs.

Vesting Schedule. The Restricted Stock will vest according to the following revenue thresholds: