Native American Graves Protection and Repatriation Act (NAGPRA) is a Congressional Act signed into law in 1990. The law is an attempt to provide a way for native people to accomplish several things including:
- protection of holy sites and religious burials from development and construction activities
- the return to proper tribes of Native American bones and artifacts stolen from them over the last 500 years, including property held by museums and universities, and
- providing more independent oversight of construction or land development sites on Indian Territory.
While in general this bill has been long overdue, and is a building block of better relations with Indian people and the US Government, it has some de facto problems.
- At what point are ancient bones of "anthropological" interest in general, and at what point are they truly bones of a given tribe? 500 year old bones? 1000 year old bones? 10,000 year old bones? If a bone were found in the US, to be 1,500,000 years old, and show evidence of Alien presence, is that still a "Native American" bone? 
- Which tribe gets to say if a location can be disturbed, or of the location under construction is a religious site?
- What happens when 2 or more tribes demand access to bones and artifacts.
Like most modern human endeavors, much of this law provides quality redress of centuries of mistreatment; however, amoral lawyers, Indian leaders, and political figures can and do abuse the law for profit or power.
- See Kennewick Man controversy and the small role NAGPRA played in the situation
- Though this example is extreme, the fact is that the law itself makes no clear distinction between bones that would clearly be the legacy of a particular tribe, and those old enough to simply be something more generally "human interest".