25 CFR §48.117

1. (a)If the Bureau determines there has been a violation of the conditions of a lease, it will promptly send the lessee and any surety and mortgagee a notice of violation, by certified mail, return receipt requested.
   1. (1)The notice of violation will advise the lessee that, within 10 business days of the receipt of a notice of violation, the lessee must:
      1. (i)Cure the violation and notify the Bureau in writing that the violation has been cured;
      2. (ii)Dispute the determination that a violation has occurred; or
      3. (iii)Request additional time to cure the violation.
   2. (2)The notice of violation may order the lessee to cease operations under the lease.
2. (b)A lessee's failure to pay compensation in the time and manner required by the lease is a violation of the lease, and the Bureau will issue a notice of violation in accordance with this section requiring the lessee to provide adequate proof of payment.
3. (c)The lessee and its sureties will continue to be responsible for the obligations in the lease until the lease expires, or is terminated or cancelled.