43 CFR 3598.1: Inspection of underground and surface conditions; surveying, estimating and study.

Operators/lessees shall provide means at all reasonable hours, either day or night, for the authorized officer to inspect or investigate the underground and surface conditions; to conduct surveys; to estimate the amount of ore or other methods of prospecting, exploration, testing, development, processing and handling; to determine the volumes, types, and composition of wastes generated; to determine the adequacy of measures for minimizing the amount of such wastes and the measures for treatment and disposal of such wastes; to determine reclamation procedures and progress; production records; environmental concerns; and to determine whether the operator/lessee is in compliance with established requirements.