According to the American Indian Higher Education Consortium, TCUs are chartered by their respective tribal governments, including the ten tribes within the largest reservations in the United States. They operate more than 75 campuses in 16 states—virtually covering Indian Country—and serve students from well more than 230 federally recognized Indian tribes. TCUs vary in enrollment (size), focus (liberal arts, sciences, workforce development/training), location (woodlands, desert, frozen tundra, rural reservation, urban), and student population (predominantly American Indian). Despite their diversity, tribal identity is the core of every TCU, and they all share the mission of tribal self-determination and service to their respective communities.