How does a tribe show that it lost its government-to-government relationship?
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
For a tribe to qualify as having lost its government-to-government relationship for purposes of § 292.7, it must show that its government-to-government relationship was terminated by one of the following means:
(a) Legislative termination;
(b) Consistent historical written documentation from the Federal Government effectively stating that it no longer recognized a government-to-government relationship with the tribe or its members or taking action to end the government-to-government relationship; or
(c) Congressional restoration legislation that recognizes the existence of the previous government-to-government relationship.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.