Code of Federal Regulations Title 43. Public Lands:  Interior § 43.3904.15 Amount of bond

(a) The BLM may increase or decrease the required bond amount if it determines that a change in amount is appropriate to cover the costs and obligations of complying with the requirements of the lease or license and these regulations. The BLM will not decrease the bond amount below the minimum (see § 3904.14(a)).

(b) The lessee or operator must submit to the BLM every three years after reclamation bond approval a revised estimate of the reclamation costs. The BLM will verify the revised estimate of the reclamation costs submitted by the lessee or operator. If the current bond does not cover the revised estimate of reclamation costs, the lessee or operator must increase the reclamation bond amount to meet or exceed the revised cost estimate.