The final environmental statement for the Crystal Dam, Reservoir, and Powerplant was filed with the Council on Environmental Quality on December 6, 1971. The statement evaluated the environmental impact from proposed construction of a double-curvature, thin-arch concrete dam and 28,000-kw hydroelectric powerplant on the Gunnison River about 15 miles east of Montrose, Colorado. Since that time there have been changes from the preliminary design concepts and additional investigations and studies to lessen the environmental impact of the proposed construction which will be discussed in this supplement.