On September 27, 1971, several environmental and conservation groups filed a lawsuit in Idaho District Court to stop the construction. Opponents of the dam questioned the project's justifications. They argued that damming a wild and scenic river and destruction of its trout fishery and other wildlife habitat would "replace a unique resource with a vulgar one." The suit questioned the economic return on investment, the bureau's compliance with the National Environmental Policy Act, and the geologic soundness of the dam's location. Concerns over the seismic conditions of the dam site delayed the bid process pending further review by the Department of the Interior. Pressure from Idaho's congressional delegation stopped the review, and in spite of the lawsuit, bids were taken in Idaho Falls on October 29, 1971. The contract was awarded to Morrison-Knudsen Co. of Boise, assisted by Peter Kiewit Sons Co. of Omaha, Nebraska. The $39 million contract was awarded in December 1971. In spite of the lawsuit, work began in February 1972. After various motions, amended complaints, attempted injunctions, and appeals, the suit was dismissed on December 23, 1974.