Indian tribes represent unique legal entities in the United States and are distinct political communities with extensive powers of self-government.
Tribal sovereignty predates the U.S. government.
Treaties, federal statutes and executive agreements over the past 200 years have established a special trust relationship between tribes and the federal government. The federal Bureau of Indian Affairs has been designated by the secretary of the interior as the primary agency to protect tribal interests and administer trust responsibilities. During the 1950s, in a move to assimilate Indians into mainstream white America, the U.S. government ended federal trusteeship of roughly three percent of the country's Indian population through a process called termination. In recent years, however, vigorous efforts have been mounted by terminated tribes to reestablish or restore the trust relationship. Oregon's Native American population is estimated at 38,496 according to the 1990 census.