If he is correct that his family has used that land since the 1800’s, then he has standing, the same as right of way.
No, he doesn’t.
His family has used this land with permission of the rightful owner, under an agreement and with payment of a fee since the days of open range ended.
Cliven Bundy refused to sign a new agreement for use of the land twenty years ago, because he disagreed with the new terms and higher grazing fee.
If you use someone else’s land under an agreement requiring payment for use, and then decide you want to keep using it without an agreement or payment, you have no right to do so, whether the land owner is a private citizen or the federal government.
If he is correct that his family has used that land since the 1800’s, then he has standing, the same as right of way.
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That used to be true. The Supreme Court has made takings arbitrary now.