If it can be proved that the…

If it can be proved that the old growth stand lies directly above a major deposit, then drilling in that area is perhaps justified. This proof should be established by responsibly drilling from off the heritage site to outline said hypothetical deposit.
Reflect on the significance of the old growth stand (history that would be erased - irreversible damage), and its tourism potential versus a limited life mineral deposit in a remote location. At the end of the day, there may not be enough values to warrant development, and the trees would be gone or the site damaged beyond remediation.
If there were a way to co-exist on the same plot, I'd like to hear it. Both sides would have to be responsible in that event.