The components of social costs included in the supply analysis are cash outlays and opportunity costs associated with harvest and alternative residue uses, potential environmental damage that is avoided by excluding unsuitable land, and costs in moving residues from farms to processing plants. Regional estimates account for the growing conditions and crops of the main agricultural areas of the United States. Estimates include the main U.S. field crops with potential for residue harvest: corn, wheat, sorghum, oats, barley, rice and cane sugar. The potential contribution of residues to U.S. energy needs is discussed.