In the year 1999, OPI [Montana Office of Public Instruction] brought together representatives from all the tribes in Montana and created 7 Essential Understandings. These are some of the major issues all tribes have in common. They form the basis for all of our curriculum efforts and initiatives. There is great diversity among the 12 tribal Nations of Montana in their languages, cultures, histories and governments. Each Nation has a distinct and unique cultural heritage that contributes to modern Montana. The seven Essential Understandings (EU) cover, but are not limited to: EU 1 Reservations: Tribal Groups; EU 2 Diversity of the American Indian; EU 3 Ideologies of Native traditional beliefs and spirituality and oral histories; EU 4 Lands reserved by the tribes; EU 5 Federal Policy Periods; EU 6 Indigenous perspectives of History; and EU 7 Tribal sovereignty.