MDU Resources Group, Inc. (NYSE:MDU) will webcast its second quarter 2013 earnings conference call August 1 following the release of its results. The webcast will begin at 10 a.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 (855) 859-2056, or (404) 537-3406 for international callers, conference ID 13007081. 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, including regulated utilities and pipelines, exploration and production, and construction materials and services. For more information about MDU Resources, see the company's Web site at www.mdu.com or contact the Investor Relations Department at firstname.lastname@example.org .