TH, as a Native American tribe receiving annuities, would use blood quantum as opposed to lineal ancestry when determining tribal membership.
In the mid-20th century, the United States government was obligated by treaties to send annuities (cash payments) to members of certain Native American Tribes. This coincided with the federal policy of termination, wherein the US government attempted to eliminate Native American identity from the country and force assimilation. Tribes could choose one of two ways to determine who qualified as a tribal member and could therefore receive annuities. The first option was meeting a certain blood quantum, or the percentage of an individual's blood that was Native American. The second was ancestry, or requiring an individual to provide documented proof that they descended from a known tribal ancestor.