Exhibit 99.1

             Press Release Announcing Retirement of Martin A. White










                                        7




                  MDU Resources CEO and Chairman White Retires

BISMARCK, N.D. - Aug. 17, 2006 -- MDU Resources Group, Inc. (NYSE:MDU) announced
today the retirement of Martin A. White, chairman and chief executive officer.
Harry J. Pearce was elected chairman of the board. Terry D. Hildestad was named
president and chief executive officer for the corporation and also was named to
the board.

"Martin has done an outstanding job in leading MDU Resources through a time of
unprecedented growth and financial success," said Pearce. "When he was elected
CEO of MDU Resources in 1997, revenues were about $607 million and earnings were
at $54 million. Revenues last year were $3.5 billion and earnings were $274.4
million. Martin would be the first person to credit his management team and his
employees for this success, but his strong leadership, unwavering integrity and
commitment to the corporation's vision statement are truly what made everything
come together."

White joined MDU Resources as vice president of corporate development in 1991
and advanced to senior vice president of corporate development. He was named
president and CEO of MDU Resources in 1997 and chairman of the board in 2001.
Before joining MDU Resources, he founded a consulting company and established a
South American mining venture. Prior to that he worked for 22 years for an
energy company based in Montana, eventually managing its mining, oil production,
technology and real estate subsidiaries. He received a bachelor's degree in
mathematics and economics from Montana State University and attended Harvard
University's Advanced Management Program and Senior Executive Update.

Forbes Magazine named MDU Resources the best-managed utility company in the
nation in 2003, and in 2004 White was named one of the Four Best Executives in
the country at the Second Annual American Business Awards. He received North
Dakota's Governor's Choice for Economic Development Ambassador of the Year Award
in 2004 and the Greater North Dakotan award in 2005. White is chairman of the
North Dakota Economic Development Foundation and the Bismarck-based University
of Mary's Board of Trustees, serves on the Plum Creek Timber Co. board and the
1st Interstate Bank board. He is currently serving as co-chairman of the United
Way Campaign. He also has served as chairman of the executive council of the
Conference Board and on the North Dakota Lewis & Clark Bicentennial Foundation
Board.



                                        8