43 CFR 3213.11 - What must I do to relinquish a lease?
Send BLM a written request that includes the serial number of each lease you are relinquishing. If you are relinquishing the entire lease, no legal description of the land is required. If you are relinquishing part of the lease, you must describe the lands to be relinquished. BLM may require additional information if necessary.