MDU Resources Group, Inc. engages in the provision of natural resource products and related services to energy and transportation infrastructure. It operates through the following business segments: Electric, Natural Gas Distribution, Pipeline and Midstream, Construction Materials and Contracting, Construction Services, and Other. The Electric segment generates, transmits and distributes electricity in Montana, North Dakota, South Dakota, and Wyoming. The Natural Gas Distribution segment distributes natural gas in Montana, North Dakota, South Dakota, Wyoming, Idaho, Minnesota, Oregon, and Washington. The Pipeline and Midstream segment offers natural gas transportation, underground storage, processing and gathering services, as well as oil gathering, through regulated and non-regulated pipeline systems and processing facilities. The Construction Materials and Contracting segment mines aggregates and markets crushed stone, sand, gravel and related construction materials, including ready-mixed concrete, cement, asphalt, liquid asphalt and other value-added products. The Construction Services segment refers to the inside and outside specialty contracting services. The company was founded by C. C. Yawkey, R.M. Heskett and Walter Alexander on March 14, 1924, and is headquartered in Bismarck, ND.