43 CFR §3903.40

1. (a)The rental rate for oil shale leases is $2.00 per acre, or fraction thereof, payable annually on or before the anniversary date of the lease. Rentals paid for any 1 year are credited against any production royalties accruing for that year.
2. (b)The BLM will send a notice demanding payment of late rentals. Failure to provide payment within 30 calendar days after notification will result in the BLM taking action to cancel the lease (see § 3934.30 of this chapter).