Code of Federal Regulations Title 43. Public Lands:  Interior § 3133.1.Rentals

(a) An annual rental shall be due and payable at the rate prescribed in the notice of sale and the lease, but in no event shall such rental be less than $3 per acre, or fraction thereof. Payment shall be made on or before the first day of each lease year prior to discovery of oil or gas on the lease.

(b) If there is no actual or allocated production on the portion of a lease that has been segregated from a producing lease, the owner of such segregated lease shall pay an annual rental for such segregated portion at the rate per acre specified in the original lease. This rental shall be payable each lease year following the year in which the segregation became effective and prior to discovery of oil or gas on such segregated portion.

(c) Annual rental paid in any year prior to discovery of oil or gas on the lease shall be in addition to, and shall not be credited against, any royalties due from production.