If he owned the land, he should have made a legal claim to it under the Homesteading Act. But he didn't. Neither did his ancestors. So clearly he doesn't own the land. And this is simply ignoring the fact that statutory law supersedes common law and the statutory law is very clear on the issue. The feds own it. End of story.
You can make this an issue of what's right and fair, but not what is legal. In both cases your opinion is monstrous. You directly support the annihilation of a species from this planet so some asshole who sucks the government teat can keep on using land he won't help maintain or protect.