25 CFR §83.12

1. (a)The petitioner may prove it was previously acknowledged as a federally recognized Indian tribe, or is a portion that evolved out of a previously federally recognized Indian tribe, by providing substantial evidence of unambiguous Federal acknowledgment, meaning that the United States Government recognized the petitioner as an Indian tribe eligible for the special programs and services provided by the United States to Indians because of their status as Indians with which the United States carried on a relationship at some prior date including, but not limited to, evidence that the petitioner had:
   1. (1)Treaty relations with the United States;
   2. (2)Been denominated a tribe by act of Congress or Executive Order;
   3. (3)Been treated by the Federal Government as having collective rights in tribal lands or funds; or
   4. (4)Land held for it or its collective ancestors by the United States.
2. (b)Once the petitioner establishes that it was previously acknowledged, it must demonstrate that it meets:
   1. (1)At present, the Community Criterion; and
   2. (2)Since the time of previous Federal acknowledgment or 1900, whichever is later, the Indian Entity Identification Criterion and Political Authority Criterion.