43 CFR § 3510.11
If I already have a Federal lease, or the mineral rights on adjacent private lands, may I lease adjoining Federal lands that contain the same deposits without competitive bidding?
June 11, 2020
Yes. If the adjoining Federal lands are available for leasing, you may lease them noncompetitively, even if they are known to contain a deposit of the mineral you are interested in leasing. We will either issue a new lease for these lands (fringe acreage) or add the lands to your existing Federal lease (modification).