Native American Graves Protection and Repatriation Act

US law passed in 1991 intended to ensure that American Indians obtain the remains of ancestors found on federal land. Nagpra dramatically increased tribal power over the disposition of human remains and cultural items held in museums. An estimated 200,000 sets of human remains are in US museums, about half of which may be culturally identifiable.

The law attempts to balance the research interests of scientists and the religious and cultural interests of tribes who hold remains as sacred and have been attempting for decades to have their ancestors' remains returned.

Remains may be impossible to identify culturally because of vague information about where they were found; a past tribal group may no longer exists; or the group may not be officially recognized by the federal government. Remains that are thousands of years old, such as Kennewick Man, might also be difficult to link with modern tribes.