The Secretary of the Interior is authorized, in his discretion, to negotiate, through any United States Indian inspector, agreements with any Indians for the cession to the United States of portions of their respective reservations or surplus unallotted lands, any agreements thus negotiated to be subject to subsequent ratification by Congress.

The Secretary of the Interior is authorized to cause to be classified or reclassified and appraised or reappraised, in such manner as he may deem advisable, the unallotted or otherwise unreserved lands within any Indian reservation opened to settlement and entry but not classified and appraised in the manner provided for in the Act or Acts opening such reservations to settlement and entry, or where the existing classification or appraisement is, in the opinion of the Secretary of the Interior, erroneous.

Nothing in this act shall change, repeal, or modify any agreements or treaties made with any Indian tribes for the disposal of their lands, or of land ceded to the United States to be disposed of for the benefit of such tribes, and the proceeds thereof to be placed in the Treasury of the United States; and the disposition of such lands shall continue in accordance with the provisions of such treaties or agreements; except as provided in sections 161 and 162 1