I've never heard Ranchers request the opportunity to purchase the land. They just want to use it as if they owned it.
I think you are talking about the fluidity of borders and lands worldwide. In reality, country borders are based on if land can be defended from other claimants (https://www.youtube.com/watch?v=4AivEQmfPpk). This is the final arbitration, even after exploring existing treaties (which arent always followed, https://www.youtube.com/watch?v=DbKNlFcg02c). The idea that the US federal government owns land until it's disseminated is one of those american myths that the US Govt tries REALLY hard to let alone, despite most federal lands being originally acquired by fiat and in the last 200 years by eminent domain (sometimes a front for private parties like the railway barons). Almost any private vs federal case can raise issues that can be elevated to the supreme court where the USG has a lot more to lose, regardless of the outcome. So they make lots of small steps, wisely. When they run into a case, even if they lose, the USG will simply work around the small setback.
But surely the state government, rather than the federal government?
Eventually the feds decide to organize a state in that area. The day Congress passes the bill of statehood, who owns the land? The new state? Only if the bill of statehood said that the land transferred.