MDU Resources Group, Inc, 1200 W Century Ave, Bismarck, ND 58503, US

Williston Basin Interstate Pipeline Company provides natural gas transportation and underground storage to customers throughout the Upper Midwest. As a subsidiary of MDU Resources Group, the company provides services to utilities, natural gas production companies, energy marketing firms and large industrial consumers. It owns and operates more than 3,700 miles of transmission, gathering and storage lines and maintains nearly 30 compressor stations. Williston Basin's system is strategically located near five natural gas producing basins, making natural gas supplies available to the company s transportation and storage customers. Its system also has 11 interconnecting points with other pipeline facilities that allows for the receipt and delivery of natural gas to and from other regions of the United States and from Canada. Williston Basin, which is regulated by the Federal Energy Regulatory Commission, maintains a headquarters location in Bismarck, N.D.

Natural Gas Corporation

Centennial Energy Holdings