Conducted under USDA Agreement No. 58-3159-7-11 Guayule Natural Rubber Program / Introduction: The United States imports 100 percent of its natural rubber. Ninety-two percent of our natural rubber production is concentrated in Southeast Asia, which is subject to interruptions through political action or direct military intervention. Natural rubber, a critical and strategic material, is necessary in such articles as aircraft and ground vehicle tires, medical supplies, resilient mounts, and certain acoustical applications. Synthetic elastomers cannot meet performance requirements in these areas. A domestic source of natural rubber will assist in assuring a supply of this critical material for industry and defense. The U.S. Department of Defense (DoD) and the U.S. Department of Agriculture (USDA) signed a Master Memorandum of Understanding in 1982 that calls for cooperation with respect to food, agriculture, forestry, nutrition, and other research of mutual interest. With this MOU both agencies adopted a supplemental agreement in 1986 that initiated the Joint Guayule Domestic Rubber Program, whose ultimate goal is to promote an economically viable domestic guayule rubber industry. To accomplish this goal, both agencies have provided funding to plant and cultivate guayule shrubs, construct a 150 -long- ton -per -year prototype plant to extract rubber from the shrubs, and conduct evaluations to establish the performance capability of military products fabricated with domestic guayule rubber. A critical component of the supplemental agreement calls for the USDA to assess the feasibility of a commercial guayule rubber processing facility of 50,000-long-ton-per-year nameplace capacity. This report, based on the best available data (1990) and on assumptions of future advancements in technology (for 1996), is designed to address the commercial prospects for the establishment of a domestic guayule rubber industry. It also examines the feasibility and factors involved in meeting either 20 percent or 100 percent of the natural rubber needs of the U.S. Department of Defense in both peacetime and national emergency conditions.