The federal government has owned the land since the Louisiana purchase. Individuals have bought the land or received it through land grants (for example the homesteader act). Over the years, they have bought some back for national parks and such. As I understand it, which could be wrong, the cattle barrens that ran those counties used the land for free for there cattle for as long as there have been cattle there. I "think" it was Teddy Roosevelt who started to put restrictions on the land for conservation purposes, and the restrictions have grown from there. Ironically, the area they are in now (as I have read) is restricted because it is a wet land that support bird migrations.
Here is my concern... if the government sales "our land" back to "the people" then it will only go to the rich or worse to corporate farms. It isn't going to go to the small rancher that really needs the lands to support his/her family. Working for the government for as long as I have, I'm sure "we the people" have over done it. I would respect them more and be willing to listen more if they were using "sit in" type tactics, but as I said before they are terrorists who just haven't killed anyone yet.