(a) The basis of volume determination for forest products sold shall be the Scribner Decimal C log rules, cubic volume, lineal measurement, piece count, weight, or such other form of measurement as the Secretary may authorize for use. With the exception of Indian tribal forest enterprises pursuant to §163.13 of this part, payment for forest products will be required in advance of cutting for timber, or removal for other forest products.

(b) Upon the request of an Indian tribe, the Secretary may provide that the purchaser of the forest products of such tribe, which are harvested under a timber sale contract, permit, or other harvest sale document to make advanced deposits, or direct payments of the gross proceeds of such forest products, less any amounts segregated as forest management deductions pursuant to §163.25 of this part, into accounts designated by such Indian tribe. Such accounts may be in one or more of the following formats:

(1) Escrow accounts at a tribally designated financial institution for receiving deposits with bids and advance deposits from which direct disbursements for timber harvested shall be made to tribes and forest management deductions accounts; or

(2) Tribal depository accounts for receiving advance payments, installment payments, payments from Indian tribal forest enterprises, and/or disbursements from advance deposit accounts or escrow accounts.

(c) The format must allow the Secretary to maintain trust responsibility through written verification that all required deposits, payments, and disbursements have been made.

(d) Terms and conditions for payment of forest products under lump sum (predetermined volume) sales shall be specified in forest product contract documents.