060-25 Wyo. Code R. § 25-6
(a) The annual rental payments on all sand and gravel, borrow material, and rip-rap rock leases shall be:
(b) Failure to pay rentals on or before the lease anniversary date shall result in termination of the lease. Termination of a lease shall not relieve the lessee of any obligation incurred under the lease other than the obligation to pay rental or penalty.
(c) After submission of the annual rental required by the lease, the production of sand and gravel, borrow material, and rip-rap rock in paying quantities, exempts lessees from submission of subsequent creditable lease annual rentals for so long as annual royalties paid meet or exceed the required annual rental amount. The annual rental shall be held for a credit on annual royalty in any year the annual royalty does not equal the required annual rental (minimum royalty) amount. Any credit amount used in making up the difference in royalty paid and the minimum lease royalty due must be paid within thirty (30) days following the next lease anniversary date to continue the lease. The Office shall notify lessees of any minimum royalty amount due after the lease anniversary for which a shortfall occurs.
060-25 Wyo. Code R. § 25-6