The Constitution did not, in itself, take away any Indian authority, but it gave to Congress and the Executive Branch of the federal government the authority which was later used to invade Indian jurisdiction it is important to realize the Constitution does not actually give the federal government any authority to govern Indian people in Indian territory. Indian jurisdiction was, officially at least, carefully respected during this early period, several states, particularly New York and Georgia, repeatedly invaded Indian jurisdiction in spite of treaties and federal laws limiting state jurisdiction. Indian people were commonly arrested and tried by state courts for alleged offenses in Indian territory. Although these were 'official' acts, they were of the same legal character as vigilante violence against Indians. Tribal governments have the power to make laws and enforce laws for tribal members living on the reservation.
Tribes generally have courts, a police force and security facilities.
Tribal governments can tax tribal members and they have the right to tax non-Indians who lease Indian lands. They can tax private companies who extract resources on tribal lands. Tribal governments make decisions about civil disputes which take place on reservation land. However, federal law enforcement officials handle major crimes that take place on Indian lands. Indian reservations are located within or in some cases across state boundaries.