MDU Resources Group, Inc. is engaged in regulated energy delivery and construction materials and services business. The Company's businesses segments are electric, natural gas distribution, pipeline and midstream, construction materials and contracting, and construction services. The electric segment generates, transmits and distributes electricity. The natural gas distribution segment distributes natural gas. The pipeline and midstream segment provides natural gas transportation, underground storage, processing and gathering services, as well as oil gathering. The construction materials and contracting segment mines aggregates and markets crushed stone, sand, gravel and related construction materials, including ready-mixed concrete, asphalt, liquid asphalt and other value-added products. The construction services segment provides utility construction services in constructing and maintaining electric and communication lines, and external lighting and traffic signalization.