30 CFR 875.19: Limited liability.

No State or Indian tribe conducting noncoal reclamation activities under the provisions of this part is liable under any provision of Federal law for any costs or damages as a result of action taken or omitted in the course of carrying out an approved State or Indian tribe abandoned mine reclamation plan. This section does not preclude liability for costs or damages as a result of gross negligence or intentional misconduct by the State or Indian tribe. For purposes of the preceding sentence, reckless, willful, or wanton misconduct will constitute gross negligence or intentional misconduct.