(a) Records are the property of the United States if they:

(1) Are made or received by a tribe or tribal organization in the conduct of a federal trust function under 25 U.S.C. §450f et seq., including the operation of a trust program; and

(2) Evidence the organization, functions, policies, decisions, procedures, operations, or other activities undertaken in the performance of a federal trust function under this part.

(b) Records not covered by paragraph (a) of this section that are made or received by a tribe or tribal organization in the conduct of business with the Department of the Interior under this part are the property of the tribe.