You are talking about royalties, not mineral rights.
Mineral rights, the right to go explore and then pay royalties on what you produce, is far less.
Again, the fed nearly always has a fire sale on the mineral rights and royalties for valuable minerals, plus there is rarely any regard to reclamation of mined lands (except for coal.) Mining companies snap up these sales, then sit on them for decades to protect the value of their current extractions.