MDU Resources Group, Inc. (NYSE:MDU) reports that its indirect wholly owned subsidiary, Fidelity Exploration & Production Company (Fidelity), has completed a study of the quantities of its estimated probable and possible natural gas and oil reserves.

The company previously reported year-end 2006 proved reserves of approximately 700 billion cubic feet equivalent (Bcfe). These reserves were prepared by the company’s technical staff and subsequently reviewed in their entirety by Ryder Scott Company LP (Ryder Scott).

In addition to its proved reserves, Fidelity has estimated that it holds approximately 800 Bcfe of probable and possible reserves, of which roughly one-half is classified as probable. Approximately 95 percent of these probable and possible reserves are in the Rocky Mountain region. These probable and possible reserve estimates were prepared by the company’s technical staff and subsequently reviewed by Ryder Scott in accordance with the probable and possible reserves definitions approved by the World Petroleum Council and the Society of Petroleum Engineers.

“We are pleased to report this information and believe it exemplifies our strong upside production potential,” said Terry D. Hildestad, president and chief executive officer of MDU Resources. “With our proved, probable and possible reserves and over five years of drilling potential from existing leaseholds, we believe our exploration and production business is well positioned to continue growing.”

The Securities and Exchange Commission (SEC) only permits disclosure of proved reserves in SEC filings. Proved oil and gas reserves are the estimated quantities of crude oil, natural gas and natural gas liquids which geological and engineering data demonstrate with reasonable certainty to be commercially recoverable in future years from known reservoirs under existing economic and operating conditions. MDU Resources uses in this release the terms probable and possible reserves, which SEC guidelines prohibit from being included in filings with the SEC. Probable reserves are unproved reserves which analysis of geological and engineering data suggests are more likely than not to be recoverable. Possible reserves are unproved reserves which analysis of geological and engineering data suggests are less likely to be recoverable than probable reserves. Estimates of probable and possible reserves are by their nature more uncertain than estimates of proved reserves and accordingly are subject to substantially greater risk of not actually being realized by the company.  Caution is given not to add together the estimated quantities in each classification without considering the significant differences in the risk of potential recovery associated with each classification.

The information in this release includes forward-looking statements, including estimated quantities of reserves, as well as statements by the president and chief executive officer of MDU Resources, within the meaning of Section 21E of the Securities Exchange Act of 1934. Although the company believes that its expectations are based on reasonable assumptions, actual results may differ materially. Important factors that could cause actual results to differ materially from those in the forward-looking statements include fluctuations in natural gas and crude oil prices, drilling successes in natural gas and oil operations, the timely receipt of necessary permits and approvals, the ability to contract for or to secure necessary drilling rig and service contracts and to retain employees to drill for and develop reserves. For a discussion of the other important factors that could cause actual results to differ, refer to Item 1A – Risk Factors in MDU Resources’ most recent Form 10-K and 10-Q.

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, and electric and natural gas utilities. 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.


Contacts:

   Financial:
     Vernon A. Raile
     Executive Vice President, Treasurer and Chief Financial Officer
     (701) 530-1003

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

   Media:
     Rick Matteson
     Director of Communications and Public Relations
     (701) 530-1700