One of the most relevant and highest growth job markets in environmental sciences is that involving Geographic Information Systems (GIS). Graduates of this comprehensive Principle of GIS course are well prepared for work and jobs with a strong GIS component. The goals of this class are therefore to provide a firm understanding of the conceptual approaches and uses of GIS (lecture), plus technical methods (lab) in GIS. The lab is taught using the latest versions of ArcGIS Desktop, ArcGIS Pro, and QGIS software. Labs plus lecture case studies address both the natural sciences and the social sciences components of environmental applications and analysis.