Okla. Admin. Code § 460:20-45-6
When no longer needed for monitoring or other use approved by the Department upon a finding of no adverse environmental or health and safety effects, or unless approved for transfer as a water well under Section 460:20-45-8, each shaft, drift, adit, tunnel, exploratory hole, entry way or other opening to the surface from underground shall be capped, sealed, backfilled, or otherwise properly managed, as required by the Department in accordance with Section 460:20-45-4 of this Subchapter and consistent with Section 30 CFR 75.1711. Permanent closure measures shall be designed to prevent access to the mine workings by people, livestock, fish and wildlife, machinery and to keep acid or other toxic drainage from entering ground or surface waters.
Okla. Admin. Code § 460:20-45-6