This proposal continues and expands the PolarTREC program that matches K-12 educators with researchers for field experiences in the Arctic and Antarctic. Annually the project will select 6-8 Arctic and 4-6 Antarctic projects to host teachers selected from nationwide applicants. Over four years, 48 teachers will go to the polar regions. The project has four objectives to: improve teacher content knowledge of multidisciplinary polar science; improve teacher instructional practices, especially the use of inquiry-based learning to translate polar science to the classroom; improve polar researchers? understanding of and engagement in K-12 education; and increase students? understanding of and engagement in the polar regions and polar science, technology, engineering, or mathematics (STEM) careers. The teacher experience includes an intense orientation focusing on having a successful field experience and translating that into the classroom, developing an education and outreach plan that focuses on their specific needs and goals, a final essay, submitting journals and photos to a website of real-time materials plus occasional live broadcasts from the field, follow up through a share fare to exchange activities and a network of teachers sharing ideas for incorporating the experience into their classrooms all backed up by external evaluation of the project using formative and summative techniques to address teacher professional development.