MDU Resources Group, Inc. (NYSE:MDU) will webcast its second quarter 2007 earnings release conference call July 24 following the release of its results. Presenting the earnings results and guidance will be MDU Resources Chief Executive Officer and President Terry D. Hildestad and Executive Vice President, Treasurer and Chief Financial Officer Vernon A. Raile.

The webcast will begin at 1 p.m. EDT and can be accessed at www.mdu.com. A webcast replay and audio replay will be available. The dial-in number for audio replay is (800) 642-1687, or (706) 645-9291 for international callers, conference ID 4877568.

MDU Resources Group, Inc., a member of the S&P MidCap 400 index, provides value-added natural resource products and related services that are essential to energy and transportation infrastructure. MDU Resources includes natural gas and oil production, natural gas pipelines and energy services, construction materials and mining, construction services, electric and natural gas utilities, and independent power production. For more information about MDU Resources, see the company’s Web site at www.mdu.com or contact the Investor Relations Department at investor@mduresources.com.

Contact:
   Phyllis A. Rittenbach
   Director of Investor Relations
   (701) 530-1057