MDU RESOURCES GROUP, INC. List of Subsidiaries (Effective December 31, 2001) State or Other Jurisdiction in Which Incorporated -------------- Alaska Basic Industries, Inc. Alaska Anchorage Sand and Gravel Company, Inc. Alaska Baldwin Contracting Company, Inc. California Bauerly Brothers, Inc. Minnesota Bell Electrical Contractors, Inc. Missouri Capital Electric Construction Company, Inc. Kansas Capital Electric Line Builders, Inc. Kansas Centennial Energy Holdings, Inc. Delaware Centennial Holdings Capital Corp. Delaware Centennial Power, Inc. Delaware Concrete, Inc. California Connolly-Pacific Co. California DSS Company California Fidelity E & P International Cayman Islands Fidelity Exploration & Production Company Delaware Fidelity Oil Co. Delaware Frebco, Inc. Ohio FutureSource Capital Corp. Delaware Hamlin Electric Company Colorado Hap Taylor & Sons, Inc. Oregon Harp Engineering, Inc. Montana ILB Hawaii, Inc. Hawaii Innovative Gas Services, Incorporated Kentucky Innovatum, Inc. Texas International Line Builders, Inc. Delaware InterSource Insurance Company Vermont JTL Group, Inc. - Montana Montana JTL Group, Inc. - Wyoming Wyoming KRC Aggregate, Inc. Delaware KRC Holdings, Inc. Delaware Knife River Corporation Delaware Knife River Dakota, Inc. Delaware Knife River Hawaii, Inc. Delaware Knife River Marine, Inc. Delaware LTM, Incorporated Oregon Loy Clark Pipeline Co. Oregon MDU Resources International, Inc. Delaware Marcon Energy Corporation Kentucky Medford Ready Mix, Inc. Delaware Morse Bros., Inc. Oregon Newco, Inc. Ohio Oregon Electric Construction, Inc. Oregon Pouk & Steinle, Inc. California Prairielands Energy Marketing, Inc. Delaware Rocky Mountain Contractors, Inc. Montana Rogue Aggregates, Inc. Oregon Utility Services, Inc. Delaware WBI Canadian Pipeline, Ltd. Canada WBI Energy Services, Inc. Delaware WBI Holdings, Inc. Delaware WBI Pipeline & Storage Group, Inc. Delaware WHC, Ltd. Hawaii Wagner-Smith Company, The Ohio Wagner-Smith Equipment Co. Delaware Wagner-Smith Pumps & Systems, Inc. Ohio Williston Basin Interstate Pipeline Company Delaware Bitter Creek Pipelines, LLC Colorado LLC Central Oregon Redi-Mix, L.L.C. Oregon LLC Netricity LLC Alaska LLC New Avoca Gas Storage LLC Texas LLC Wagon Box Partners, LLC Colorado LLC Hawaiian Cement Hawaii Partnership MDU Resources Luxembourg I LLC S.a.r.l. Luxembourg MDU Resources Luxembourg II LLC S.a.r.l. Luxembourg MDU Brasil Ltda. Brazil