BISMARCK, N.D. — Jan. 10, 2023 — MDU Resources Group, Inc. (NYSE: MDU) announced today that Nathan W. Ring has been named chief financial officer of the company’s wholly owned construction materials subsidiary, Knife River Corporation, effective upon completion of the planned separation of Knife River. Ring currently is vice president of business development at Knife River. MDU Resources previously announced it expects its spinoff of Knife River into an independent, publicly traded company to…