TeenMaptivists is a national network of high-school, student-led chapters. We collaborate with humanitarian and geospatial organizations on mapping tasks that respond to development and humanitarian needs around the world. Through guest speakers, field mapping, national mapathons, and tailored training workshops, we are instilling the power of community and importance of activism in students. Through publicly available, open-source GIS platforms, students can leverage the power to make a difference in their communities.