The real question here is, who owns this "open land"? The text of the document linked in the OP states that:
(ii ) " Open land " means land outside the exterior boundaries of any incorporated city, town, subdivision
So, the land isn't owned by some city or town. Is it nationally-, state- or county-owned? If so, that's public land, and taxpayers have a right to
be there. If it's privately-owned, that is another matter. One segment uses the phrase, "private open land", which makes no sense. Private property
is private, not "open". Why add the word "private" to such a document?
If this is actual public land, and the issue is cattle grazing, how is the cattle there? Do people lease form the government? Not my area of study,
so I am not familiar with this situation at all. If that's the case, under what system is it determined that cattle grazing isn't harmful, or is
beneficial? Who makes such decisions? I do know that, on the post where we have been, farmers bid to be allowed to harvest hay in many fields. In
that case, the wildlife is thriving, with more deer, for example, than just off-post. No, that isn't grazing, but it is a change. And it isn't just
deer, either; other species thrive there as well - coyote, raccoon, rabbits, squirrels, chipmunks, wild turkeys, geese in season, owls, foxes, etc.
It sounds like the issue here is that some claim the cattle are harming the lands, and that there are perhaps issues with data collecting. Who has
done such collecting, and under what conditions? To warrant such a law, there would need to be some real issues.