Okla. Admin. Code § 460:20-43-51
(a) General. All disturbed areas shall be restored in a timely manner to conditions that are capable of supporting:
(c) Criteria for alternative postmining land uses. Higher or better uses maybe approved by the Department as alternative postmining land uses after consultation with the landowner or the land management agency having jurisdiction over the lands, if the proposed uses meet the following criteria:
(3) The use will not:
(d) Approximate original contour. Criteria for variance. Surface coal mining operations that meet the requirements of this Subsection may be conducted under a variance from the requirement to restore disturbed areas to their approximate original contour, if the following requirements are satisfied: