The Rapid Ecoregional Assessments (REAs) were launched in 2010 to help improve the understanding of existing condition for ecoregions and how conditions may be altered by ongoing environmental changes and land use. They do not allocate resource uses or make management decisions. They provide science-based information and tools for land managers and stakeholders to consider in subsequent resource planning and decision making processes. REAs examine ecological values, conditions, and trends within large, connected areas that have similar environmental characteristics in order to capitalize on efficiency of scale. REAs provide context to make site-specific decisions and conduct analyses for resource management plans and National Environmental Policy Act processes. The REAs seek to identify important resource values and patterns of environmental change that may not be evident when managing smaller, local land areas.This report contains Phase I or Pre-Assessment for the Chihuahuan Desert Rapid Ecoregional Assessment including an overview of the ecoregion, Conservation Elements, Change Agents, and Conceptual Models. Contact: BLM_OC_REA_Data_Portal_Feedback_Team@blm.gov