Knife River Proxy Materials

Proxy Voting
The Board of Directors is furnishing proxy materials to solicit proxies for use at the Annual Meeting of Stockholders on May 20, 2026, and any adjournment(s) thereof. If you are a stockholder of record at the close of business on March 27, 2026, you are encouraged to vote in advance of the meeting using one of the following voting methods:

Registered Stockholders:
If your shares are held directly with our stock registrar, you will receive either a Notice Regarding Availability of Proxy Materials (Notice) or a Proxy Card with the proxy materials. You can vote your shares any one of four ways:

The Internet:
Go to the website shown on your Notice or Proxy Card, if you received one, and follow the instructions.

By Telephone:
Call the telephone number shown on the Notice or Proxy Card, if you received one, and follow the instructions given by the voice prompts.

Voting via the Internet or by telephone authorizes the named proxies to vote your shares in the same manner as if you marked, signed, dated, and returned a Proxy Card by mail. Your voting instructions may be transmitted up until 11:59 p.m. Eastern Time on May 19, 2026.

By Mail:
If you received paper copies of the Proxy Statement, Annual Report, and Proxy Card, mark, sign, date, and return the Proxy Card in the postage-paid envelope provided.

During the Meeting:
You may vote virtually at www.virtualshareholdermeeting.com/KNF2026.

Annual Meeting Webcast
Knife River Corporation will webcast its Annual Meeting of Stockholders at 10 a.m. CDT May 20. The link below to access the webcast will be active at 9:45 a.m. CDT May 20.