(a) In sales of forest products with an appraised stumpage value exceeding $15,000, the contract forms approved by the Secretary must be used unless a special form for a particular sale or class of sales is approved by the Secretary.

(b) Unless otherwise directed, the contracts for forest products from individually-owned Indian land will be paid by remittance drawn to the Bureau of Indian Affairs and transmitted to the Superintendent. Upon the request of the tribe, the contracts for tribal forest products may require that the proceeds be paid promptly and directly into a bank depository account designated by such tribe, or by remittance drawn to the Bureau of Indian Affairs and transmitted to the Superintendent.

(c) By mutual agreement of the parties to a contract, contracts may be extended, modified, or assigned subject to approval by the approving officer, and may be terminated by the approving officer upon completion or by mutual agreement.