How to register as a native american<br>Retain copies of your parents' or families' tribal records. This is the best way to find out the tribe and the connection you have to a native american tribe. You will be able to use copies of these records to prove you are a descendant of a tribe member, and possibly to prove your blood quantum.
Native Americans keep family records. 
The article assumes families keep written records but who knows.  Many native tribes have a oral tradition.  Its all about using the right keywords for this one i think. 
( z1 keep :ARG0 ( z2 person :mod ( z3 ethnic-group :name ( z4 name :op "Native" :op "American" ) ) ) :ARG1 ( z5 record :mod ( z6 family ) ) )