MDU Construction Services Group, Inc.

MDU Construction Services Group provides industry-leading utility construction services. The diverse group of companies specializes in constructing and maintaining electric and communications lines, gas pipelines, fire suppression systems, and external lighting and traffic signalization. The companies also provide expertise in utility excavation and inside electrical and mechanical services, and manufacture and distribute transmission line construction equipment and supplies. MDU Construction Services Group is authorized to operate in 42 states.

MDU Resources Group, Inc.

Founded in 1924, MDU Resources Group provides essential products and services through two lines of business: regulated energy delivery and construction materials and services. The company has been traded on the New York Stock Exchange since 1948 under the symbol MDU.