It is estimated (by some) that there were perhaps four million people here when Columbus landed. All were 100% Native American. I'd be surprized if there were four million such today, but watered down, those genes are probably present in everyone who's family has been here long enough.I know for sure the Cherokees will accept you if you're 25% and your name is on the rolls. The only tribes I know of that can claim to be more or less intact are the southwestern ones, principally the Navajo.