Two utility subsidiaries of MDU Resources Group Inc. (NYSE: MDU), have been recognized for highest customer satisfaction. Intermountain Gas Company and Cascade Natural Gas Corporation received the highest ranking in satisfaction among residential natural gas customers in the midsize natural gas utilities segment of the West Region in a tie, according to a national study. The 2013 J.D. Power Gas Utility Residential Customers Satisfaction Study SM was released last week. Intermountain and Cascade earned a score of 655, tied for highest among midsize natural gas utilities in the West Region. This is the fourth straight year Intermountain has earned the top spot. “There can be no higher compliment than hearing from your own customers that they think you are the best,” said David L. Goodin, president and CEO of MDU Resources. “This is an outstanding recognition for our employees who make it their highest priority every day to provide safe and reliable natural gas service,” said K. Frank Morehouse, president and CEO of Intermountain and Cascade. “Our employees take great pride in serving our more than 264,000 Cascade customers in Washington and Oregon, and our more than 312,000 Intermountain customers in southern Idaho.” In its 12 th year, the study surveys customer satisfaction across a number of factors, including billing and payment, price, corporate citizenship, communications, field service and customer service. 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 website at www.mdu.com or contact the Investor Relations Department at firstname.lastname@example.org. Intermountain Gas Company is a natural gas distribution company serving approximately 312,000 residential, commercial and industrial customers in 74 communities in southern Idaho. For more information about Intermountain, visit www.intgas.com.Cascade Natural Gas is a natural gas distribution company serving approximately 264,000 residential, commercial, industrial and transportation customers in 96 communities in Washington and Oregon. For more information about Cascade, visit www.cngc.com.