25 U.S.C. § 407d

The Secretary of the Interior is authorized to charge purchasers of timber on Indian lands that are held by the United States in trust, or that are subject to restrictions against alienation or encumbrance imposed by the United States, for special services requested by the purchasers in connection with scaling, timber marking, or other activities under the contract of purchase that are in addition to the services otherwise provided by the Secretary, and the proceeds derived therefrom shall be deposited to the credit of the appropriation from which the special services were or will be provided.