(a) The lessee, permittee or prospective lessee acquiring a lease, or any interest therein, by assignment shall furnish with each lease, permit or assignment a surety bond or personal bond in an amount sufficient to ensure compliance with all of the terms and conditions of the lease(s), permit(s), or assignment(s) and the statutes and regulations applicable to the lease, permit, or assignment. Surety bonds shall be issued by a qualified company approved by the Department of the Treasury (see Department of the Treasury Circular No. 570).

(b) An operator may file a $75,000 bond for all geothermal, mining, or oil and gas leases, permits, or assignments in any one State, which may also include areas on that part of an Indian reservation extending into any contiguous State. Statewide bonds are subject to approval in the discretion of the Secretary.

(c) An operator may file a $150,000 bond for full nationwide coverage to cover all geothermal or oil and gas leases, permits, or assignments without geographic or acreage limitation to which the operator is or may become a party. Nationwide bonds are subject to approval in the discretion of the Secretary.

(d) Personal bonds shall be accompanied by:

(1) Certificate of deposit issued by a financial institution, the deposits of which are federally insured, explicitly granting the Secretary full authority to demand immediate payment in case of default in the performance of the provisions and conditions of the lease or permit. The certificate shall explicitly indicate on its face that Secretarial approval is required prior to redemption of the certificate of deposit by any party;

(2) Cashier's check;

(3) Certified check;

(4) Negotiable Treasury securities of the United States of a value equal to the amount specified in the bond. Negotiable Treasury securities shall be accompanied by a proper conveyance to the Secretary of full authority to sell such securities in case of default in the performance of the provisions and conditions of a lease or permit; or

(5) Letter of credit issued by a financial institution authorized to do business in the United States and whose deposits are federally insured, and identifying the Secretary as sole payee with full authority to demand immediate payment in the case of default in the performance of the provisions and conditions of a lease or permit.

(i) The letter of credit shall be irrevocable during its term.

(ii) The letter of credit shall be payable to the Bureau of Indian Affairs upon demand, in part or in full, upon receipt from the Secretary of a notice of attachment stating the basis thereof (e.g., default in compliance with the lease or permit provisions and conditions or failure to file a replacement in accordance with paragraph (d)(5)(v) of this section).

(iii) The initial expiration date of the letter of credit shall be at least one (1) year following the date it is filed in the proper Bureau of Indian Affairs office.

(iv) The letter of credit shall contain a provision for automatic renewal for periods of not less than one (1) year in the absence of notice to the proper Bureau of Indian Affairs office at least ninety (90) days prior to the originally stated or any extended expiration date.

(v) A letter of credit used as security for any lease or permit upon which operations have taken place and final approval for abandonment has not been given, or as security for a statewide or nationwide bond, shall be forfeited and shall be collected by the Secretary if not replaced by other suitable bond or letter of credit at least thirty (30) days before its expiration date.

(e) The required amount of bonds may be increased in any particular case at the discretion of the Secretary.