Yeah, like the California gold fields, Colorado's silver mines, and the Comstock Lode.
I don't remember anything about their trying to "take away" federal property like Fort Bridger and Fort Osage, either. They walked away from the northern Territories, claimed New Mexico, Arizona, and Oklahoma. All else they gave up -- but you never complain about that, only about the part of the ledger where something might have stuck to them. I don't think fairness or equity is your concern here.
They had no claim to that, any more than New York or Pennsylvania did. Those were the property of the feds.