I've always found it very bizarre the criteria used to consider a person as an 'indigenous' American. I used to think it was a combo of purity of the bloodline/family tree as well as physical appearance but I've heard of instances where famous unis admit and give generous scholarships to individuals with extremely minimal Native heritage(as in they look White, have a totally White-sounding name and cultural attitudes and the last pure indigenous person in their family tree was many generations ago). Ironically enough, Black+Native mixes aren't even considered as legit indigenous.