Teaching Environmental Science is a professional development, summer environmental institute which for nine years has enlightened K-12 in-service teachers at more than a dozen Texas universities. The institutes are co-mentored by the Texas Natural Resource Conservation Commission and local universities. The TES curriculae focus on three broad areas of study: air quality, water quality and quantity, and waste disposal issues. The diversity of Texas landscapes including piney woods, coastal beaches, arid mountains, fertile agricultural regions, and subtropical habitats along the Rio Grande Valley, creates a regional outdoor laboratory in which teachers learn to engage students. TES participants are multi-generational, multi-cultural, and multi-ethnic. Teachers earn three hours of scholarship-paid graduate credit and with less than 25 participants per institute, become comfortable exploring and learning together. Each university syllabus features expert speakers from industry and government partnerships and non-profit organizations who provide balanced, scientifically-based information. TES charters a course to enrich and energize teachers so that they actively involve students in addressing global environmental problems and their solutions. Field trips address a variety of topics including: petrochemical, ore smelting and paper-making industrial waste treatment; municipal waste treatment; hazardous waste incineration; canoeing in endangered habitats with State and National Park naturalists; soil remediation of industrial sites; air boat exploration of estuaries guided by the Texas General Land Office Oil Spill Division and the U.S. Coast Guard; preservation of wildlife habitats in industrial settings; demonstration farms to study the best management practices, non-point sources, and pest management; fish hatcheries to study water consumption and discharge; beaches to study coastal erosion; and the National Marine Fisheries Service ridley sea turtle headstart program. The TES model has enormous potential to make K-12 teachers more aware of current environmental issues and should be replicated across the nation.