Teachers on the Leading Edge (TOTLE) is an Earth science teacher professional development program featuring Pacific Northwest active continental margin geology. Teacher training workshops and teaching resources are developed primarily for grades 6 though 8 in which Earth science is most often taught. Program themes include geologic hazards as incredible but understandable aspects of living on the “leading edge” of the North American continent. Fundamental concepts and observations progress from global patterns, to regional context, and then to local applications. For example, earthquakes are concentrated near tectonic plate boundaries such as the Cascadia subduction zone between the Juan de Fuca and North American plates. Earthquake hazards include liquefaction and landslides that are affected by regional and local geology. And relative earthquake hazard maps provide comparisons of hazards on county, city, and neighborhood scales. TOTLE master teachers and Geoscience educators have developed inquiry-based lesson plans for middle school learners of Earth science that translate Pacific Northwest geologic-hazards research from the US Geological Survey, the Oregon Department of Geology and Mineral Industries, and the Washington State Department of Natural Resources. Many TOTLE middle school lesson plans are regional adaptations of teaching resources developed by IRIS (e.g. BOSS model and Build a Better Wall) and UNAVCO (e.g. Plate Boundary Observatory GPS data analyses). We emphasize the importance of zoning regulations, infrastructure engineering, and emergency preparedness in preventing geologic hazards damage, injuries, and deaths in order to: (1) demonstrate how improvements in Geoscience knowledge have led to improved engineering designs that mitigate hazards; (2) align lessons with national and state K-12 science education standards that focus on science, technology, and societal connections; and (3) avoid fatalism and develop a culture of geologic hazards awareness among future citizens of the Pacific Northwest. Participants in TOTLE – EarthScope workshops receive an extensive collection of maps, posters, and experimental apparatus. These teaching resources greatly facilitate teachers' transfer of workshop learning to their classroom teaching of Earth science.