(a) Any Indian group in the continental United States that believes it should be acknowledged as an Indian tribe and that it can satisfy the criteria in Sec. 83.7 may submit a letter of intent.
(b) Letters of intent requesting acknowledgment that an Indian group exists as an Indian tribe shall be filed with the Assistant Secretary--Indian Affairs, Department of the Interior, 1849 C Street, NW., Washington, DC 20240. Attention: Branch of Acknowledgment and Research, Mail Stop 2611-MIB. A letter of intent may be filed in advance of, or at the same time as, a group's documented petition.
(c) A letter of intent must be produced, dated and signed by the governing body of an Indian group and submitted to the Assistant Secretary.