Tribal Colleges and Universities (TCUs) are chartered by their respective tribal governments, including the ten tribes within the largest reservations in the United States. The 35 accredited TCUs operate more than 90 campuses and sites in 15 states—covering most of Indian Country—and serve students from well more than 250 federally recognized Indian tribes. TCUs vary in enrollment (size), focus (liberal arts, sciences, workforce development/training), location (woodlands, desert, frozen tundra, rural, urban), and student population (predominantly American Indian). However, tribal identity is the core of every TCU, and they all share the mission of tribal self-determination and service to their respective communities.These academically rigorous institutions engage in partnerships with organizations including U.S. Department of the Interior, U.S. Department of Agriculture, U.S. Department of Housing and Urban Development, the National Science Foundation, National Aeronautics and Space Administration, and universities nationwide to support research and education programs that focus on issues such as climate change, sustainable agriculture, water quality, wildlife population dynamics, and diabetes prevention. Many support distance learning involving state-of-the-art learning environments.