060-20 Wyo. Code R. § 20-7
(a) Royalties for trona/sodium shall be based on the terms of the effective leases issued therefor, subject to all state royalty statutes and rules, and shall be required based on the total consideration received for state production. Leases for trona/sodium shall provide for payment of the following royalty rate, unless a different rate is specifically authorized by the Board:
(b) After a trona/sodium lease becomes an operating lease, the Board may reduce the royalty payable to the state, as to all or any of the lands or formations covered by the lease, if it determines that such a reduction is necessary to allow the lessee to undertake operations or to continue to operate with a reasonable expectation that the operations will be profitable. Such a reduction in the royalty payable to the state shall in all cases be conditioned upon the cancellation of all cost-free interests. The Board may also impose other conditions to the reduction in royalty.
060-20 Wyo. Code R. § 20-7