Free: Contests & Raffles.
At the end of the day, I don't think many people will look back 30 years from now and say "geeze, not mining that piece of ground was sure a mistake." I'm not naive to think that the stuff I buy magically appears out of nothing, but I would rather see commodity prices increase then to see new mines or other non-renewable extraction from land. If that means making it a monument, then sure. We can always go back in the future and dig it up but we can't ever put it back once its all torn up and leased out.
His recent podcast on the state of the Union is probably the most important and succinct thing an outdoorsman should listen to this year. Phenomenally well spoken advocate for hunting, fishing and the outdoors