Section 163.21 - Bonds required(a) Performance bonds will be required in connection with all sales of forest products, except they may or may not be required, as determined by the approving officer, in connection with the use of forest products by Indian tribal forest enterprises pursuant to this part in § 163.13 or in timber cutting permits issued pursuant to § 163.26 of this part.(1) In sales in which the estimated stumpage value, calculated at the appraised stumpage rates, does not exceed $15,000, the bond shall be at least 20 percent of the estimated stumpage value.(2) In sales in which the estimated stumpage value exceeds $15,000 but is not over $150,000, the bond shall be at least 15 percent of the estimated stumpage value but not less than $3,000.(3) In sales in which the estimated stumpage value exceeds $150,000, but is not over $350,000, the bond shall be at least 10 percent of the estimated stumpage value but not less than $22,500.(4) In sales in which the estimated stumpage value exceeds $350,000, the bond shall be at least 5 percent of the estimated stumpage value but not less than $35,000.(b) Bonds shall be in a form acceptable to the approving officer and may include: (1) A corporate surety bond by an acceptable surety company;(2) A cash bond designating the approving officer to act as trustee under terms of an appropriate trust;(3) Negotiable U.S. Government securities supported by an appropriate trust instrument; or(4) An irrevocable letter of credit.