36 C.F.R. § 9.143
When will the NPS release my financial assurance?
We will release your financial assurance within 30 days after the Regional Director:
(a) Determines that you have met all applicable reclamation operating standards and any additional reclamation requirements that may be included in your operations permit; or
(b) Accepts a new operator's financial assurance under § 9.160(b) or (c).