MDU Resources Group engages in the regulated energy delivery, construction materials and services businesses. The Company's Electric segment generates, transmits, and distributes electricity. The Natural Gas Distribution segment distributes natural gas and offers related value-added services. The Pipeline and Midstream segment provides natural gas transportation, underground storage, processing, and gathering services, as well as oil gathering and processing facilities. It also provides cathodic protection and other energy-related services. The Construction Materials and Contracting segment mines aggregates and markets crushed stone, sand, gravel, and related construction materials, and provides integrated contracting services. The Construction Services segment constructs and maintains electric and communication lines, gas pipelines, fire suppression systems, and external lighting and traffic signalization equipment.