Montana Power Company, a Corporation v. Environmental Protection Agency, and Northern Cheyenne Tribe and Northern Plains Resource Council, Intervenors. Montana Power Company, a Corporation v. Environmental Protection Agency, and Northern Plains Resource Council and Northern Cheyenne Tribe, Intervenors-Appellants. The Montana Power Company, Washington Water Power Company, Puget Sound Power and Light Company, Portland General Electric Company and Pacific Power and Light Company v. Environmental Protection Agency

608 F.2d 334 13 ERC 1385 , 9 Envtl. L. Rep. 20 ,667 MONTANA POWER COMPANY, a corporation, et al., Plaintiffs-Appellees, v. ENVIRONMENTAL PROTECTION AGENCY et al., Defendants-Appellants, and Northern Cheyenne Tribe and Northern Plains Resource Council, Intervenors. MONTANA POWER COMPANY, a corporation, et al., Plaintiffs-Appellees, v. ENVIRONMENTAL PROTECTION AGENCY et al., Defendants, and Northern Plains Resource Council and Northern Cheyenne Tribe, Intervenors-Appellants. The MONTANA POWER COMPANY, Washington Water Power Company, Puget Sound Power and Light Company, Portland General Electric Company and Pacific Power and Light Company, Petitioners-Appellants, v. ENVIRONMENTAL PROTECTION AGENCY, Respondent-Appellee. Nos. 77-2521, 77-2253 and 78-1140. United States Court of Appeals, Ninth Circuit. July 16, 1979. John L. Peterson, Butte, Mont., for Montana Power Co. Bruce J. Terris, Washington D. C. (argued), Larry G. Gutterridge, Dept. of Justice, Washington, D. C., for E. P. A. Appeals from the United States District Court for the District of Montana. On Petition to Review a Decision of the Environmental Protection Agency. Before MERRILL and WRIGHT, Circuit Judges, and SWEIGERT,…