Watershed investigations using geospatial tools offer a compelling although challenging way to connect students with their local and regional environment and promote understanding of ecological concepts. The NSF-funded Inquiring with GIS project combines comprehensive curriculum, extensive support, and educational tools to help Central Appalachian middle and high school teachers incorporate GIS-based watershed studies into their existing curricula. Aligned with state standards and built on the Learning-for-Use design framework, the iGIS supplementary curriculum seeks to motivate students with a watershed assessment assignment. It provides firsthand experiences to learn watershed/stream ecology and allows students to apply their new understanding to assess land use impacts on stream health in local and regional watersheds. Throughout, students engage in activities to learn and apply visualization and analysis skills using a GIS software program and data specifically designed for the classroom. During project workshops and an online session, teachers work through the curriculum like students and develop implementation plans. They practice their new skills with summer students and implement the supplementary curriculum in the classroom with regular follow-up support and project meetings. On-going evaluation is assessing changes in student and teacher attitudes and understanding with pre/post surveys, feedback surveys, and embedded assessments. Preliminary results indicate the teacher professional development model is effective and that students are demonstrating knowledge about watershed ecology.