MDU Resources
| Company type | Public |
|---|---|
| Industry | Energy, Utilities, Construction Materials |
| Predecessor | Minnesota Northern Power Company |
| Founded | 1924 |
| Founder | Rolland Heskett |
| Headquarters | Bismarck , United States |
Area served | 48 U.S. states |
| Products | Energy distribution, natural gas, electric utilities, construction materials |
MDU Resources Group, Inc. is an American corporation delivering products and services to regulated energy distribution and utilities-related construction materials sectors. Headquartered in Bismarck, North Dakota, the company operates across 48 states.
Early history
The origins of MDU Resources trace back to 1924 when it was established as the Minnesota Northern Power Company by Rolland Heskett, who brought prior utility expertise from Wisconsin and northeastern Minnesota. Its earliest assets included an electric utility in Cushing, Oklahoma (later divested to Oklahoma Gas & Electric), the Minnesota Electric Light & Power Company serving Bemidji, Minnesota (sold in 1925), and two utilities in Eastern Montana located in Sidney, Glendive, and Fairview. These Montana utilities became the foundation for what evolved into Montana-Dakota Utilities' operations.
Initially centered on electric power sales, the company ventured into the natural gas sector after discovering oil in 1936 within the Williston Basin of Eastern Montana. It expanded its footprint throughout Eastern Montana and western North Dakota, securing the electric franchise for Miles City after competing against Montana Power Company.
Following the enactment of the Public Utility Holding Company Act of 1935 (PUHCA), Heskett consolidated all gas and electric subsidiaries under the new corporate identity of Montana-Dakota Utilities.
Later history
Distinct from neighboring utility companies, MDU typically refrained from wholesale energy resale, with the exception of five Eastern Montana communities served by Mountain States Power Company, whose distribution networks MDU had acquired by the early 1940s.
MDU’s common shares were first listed on the New York Stock Exchange in 1948 under the symbol MDU. By the 1960s, the company transitioned its headquarters to Bismarck—its largest service market—finalizing this relocation in 1968.
In 1985, a corporate restructuring led to the formation of MDU Resources Group, Inc. The company diversified into construction materials through its 1992 acquisition of an aggregates mining business based in central California. Knife River Corporation, a subsidiary of MDU, has grown to become one of the nation’s leading sand and gravel producers after ceasing coal mining operations in 2001.
The utility services division was established by MDU in 1997 and later developed into what is now known as MDU Construction Services Group. In 2024, this division underwent rebranding as Everus Construction Group, Inc., preceding a planned tax-free spin-off.
Acquisition and lawsuit
MDU's most significant expansion in electric utilities took place in 1945 with its acquisition of Dakota Public Service Company (DPSC) from NorthWestern Public Service Company (NWPS). DPSC provided service to 91 communities across North Dakota and South Dakota. Following this purchase, MDU engaged in six years of legal disputes with NWPS concerning contested internal charges among NWPS subsidiaries. The litigation concluded without resolution as both parties acknowledged its futility.
Afterward, MDU concentrated on addressing increasing electricity and natural gas demand within its enlarged service area. During the late 1960s, MDU collaborated with NWPS and Otter Tail Power to construct the Big Stone power plant near Big Stone City, South Dakota. These partners have since worked jointly on two base-load generating facilities: Big Stone and Coyote.
2016 Portland Gas Explosion – Lawsuits Involving Loy Clark
The Oregon Public Utility Commission determined that Loy Clark, a subsidiary of MDU, was accountable for the 2016 Portland gas explosion which resulted in the destruction of a building, widespread asbestos contamination, damage to several nearby structures, and injuries to eight individuals. The total damages were assessed at $17.2 million. The PUC faulted Loy Clark for insufficient communication with regulatory authorities regarding their excavation activities. Furthermore, OSHA imposed fines on Loy Clark due to safety breaches connected to the event. In November 2018, ten legal actions were initiated against Loy Clark, including two lawsuits from insurers who had settled claims, with an additional two lawsuits filed in December 2019.
Subsidiaries
MDU Resources expanded its portfolio by acquiring Cascade Natural Gas Corporation in 2006, which supplies natural gas to regions in Oregon and Washington. Two years later, in 2008, Intermountain Gas Company, serving parts of Idaho, was added to MDU’s holdings. In 2023, MDU completed the spin-off of Knife River Corporation—a company specializing in construction materials and contracting services such as aggregates, asphalt products, cement, liquid asphalt, building supplies, and ready-mix concrete—operating across 17 states as an independent publicly traded entity.