Hi Sharon. You have to use exactly the correct descendancy when you use dna for research.
yDNA passes from father to son. Women never have it. A yDNA (surname) research is for the father's-father's ... father's paternal line of the man being tested. There can be no woman in the ancestry between the man your are testing and the ancestor of interest.
mtDNA passes from mother to child. Men have it, but cannot pass it on. A mtDNA research is for the mother's-mother's ... mother's maternal line. The only place that a man can be in the sequence between the participant and the ancestor of interest is as participant. If you connect through a male ancestor to get to the ancestor of interest (ie the Native American) it won't work. You need to find a living descendant whose mother's mother's ... is the ancestor of interest.
There is more info in our Frequently Asked Questions