This environmental impact statement assesses the effects of offtract disposal of waste materials associated with a proposed open pit mine on Federal Prototype Oil Shale Lease Tract C-a. The proposed action is to place retorting and other facilities, plus waste materials on an area adjacent to Tract C-a known as 84 Mesa. Alternative sites for waste disposal were investigated in areas known as Philadelphia Creek and the West Fork of Spring Creek. Additionally, a no action alternative was evaluated in which no offtract leasing would occur, but all facilities and wastes would be placed within the existing lease boundaries of Tract C-a. The decision making process involved in the selection of preferred alternative included consideration of environmental factors, safety factors, resource management considerations pertinent to the mineral rich Piceance Basin, and the overall goals of the Federal Prototype Oil Shale Leasing Program.