From the sounds of things, private citizens “found” it and the FBI is now in the process of confiscating it.
Grabbing money seems to be the one area where police excel.
If it was government gold, doesn’t matter who found it, it still belongs to the government. Perhaps if you ask really nicely, they’ll give you a finders’ fee.
It is on state land so I believe it would belong to the state. If it had been found on private land I’d share your concern.