Data supports that throughout the last four decades the Western Joshua Tree (Yucca brevifolia) has been negatively impacted by wildfires and land development. Our research was conducted to add to the California Fish and Wildlife peer-reviewed status report in their decision to list the Western Joshua Tree (WJT) as a threatened species under the California Endangered Species Act. The data used in this study were ArcGIS Pro ESRI-supported shapefiles from 1980 - 2020 created by government agencies and nonprofit organizations. The data collected was then synthesized into maps showing the growing threat over the last 40 years. tanner_chapman@redlands.edu joshua_thompson@redlands.edu tim_krantz@redlands.edu