Spatial skills are an essential foundation for success in STEM fields, yet spatial skills are not explicitly taught in school. One powerful technological tool for teaching spatial skills is Geographic Information Systems (GIS). The Geospatial Explorers project builds upon the successful Geospatial Semester program (GSS) at James Madison University and at the Chicago Public Schools. GSS uses GIS to support students in their development of geospatial problem-solving skills and the application of those skills to extended local problems that they self-select. Prior research has shown that using GIS for problem solving can facilitate spatial habits of mind and can increase the foundational reasoning and argumentation skills that are seen as critical for STEM success. Moreover, exposure to just one GIS unit can significantly increase students' spatial reasoning abilities and increase student interest in pursuing STEM careers. The Geospatial Explorers project aims to expand on the success of GSS by co-developing, implementing, and studying the impact of four GIS technology-enhanced curricular units per year in each of Career and Technical Education (CTE) business, science, social studies, and health classes in high schools in the U.S. territory of Puerto Rico. The Geospatial Explorers project will collaborate with the regional director of the Mayaguez region of Puerto Rico to identify and support high schools that can enact GIS across all four disciplines. The Geospatial Explorers