43 CFR 3142.1 - Diligent development.
A lessee shall have met his/her diligent development obligation if:
(a) The lessee is conducting activity on the lease in accordance with an approved plan of operations; and
(b) The lessee files with the authorized officer, not later than the end of the eighth lease year, a supplement to the approved plan of operations which shall include the estimated recoverable tar sand reserves and a detailed development plan for the next stage of operations;
(c) The lessee has achieved production in paying quantities, as that term is defined in § 3142.0-5(a) of this title, by the end of the primary term; and
(d) The lessee annually produces the minimum amount of tar sand established by the authorized officer under the lease in the minimum production schedule which shall be made part of the plan of operations or pays annually advance royalty in lieu of this minimum production.