existence as an Indian tribe, together with the factual exposition and all documentary evidence necessary to demonstrate that these arguments address the mandatory criteria. (7) Historically, historical or history The term historically, historical or history means dating from first sustained contact with non-Indians. (8) Indian group or group The term Indian group or group means any Indian or Alaska Native aggregation within the continental United States that the Secretary of the Interior does not acknowledge to be an Indian tribe. Indian tribe, also referred to herein as tribe, means any Indian or Alaska Native tribe, band, pueblo, village, or community within the continental United States that the Secretary of the Interior has lawfully acknowledged as an Indian tribe. (9) Indigenous The term indigenous means native to the continental United States in that at least part of the petitioner’s territory at the time of sustained contact extended into what is now the continental United States. (10) Informed party The term informed party means any person or organization, other than an interested party, who requests an opportunity to submit comments or evidence or to be kept informed of general actions regarding a specific petitioner. (11) Interested party The term interested party means any person, organization or other entity who can establish a legal, factual or property interest in an acknowledgment determination and who requests an opportunity to submit comments or evidence or to be kept informed of general actions regarding a specific petitioner. Interested party includes the governor and attorney general of the State in which a petitioner is located, and may include, but is not limited to, local governmental units, and any recognized Indian tribes and unrecognized Indian groups that might be affected by an acknowledgment determination. (12) Letter of intent The term letter of intent means an undocumented letter or resolution by which an Indian group requests Federal acknowledgment as an Indian tribe and