The U.S. Department of Defense is responsible for managing over 25 million acres of land using a variety of programs, tools, and procedures to periodically assess and evaluate land condition. One tool, the ECOTONE model, was set up to simulate vegetation recovery from military disturbances on Fort Bliss, Texas, as a conceptual structure to prioritize the research efforts in land management. This report provides documentation of the structure and function of the ECOTONE model. The model consists of processes - dispersal, establishment, growth, etc. - that flow into each other and are influenced by disturbances that result in varying degrees of plant mortality.