Bob your right I just read it wrong, sorry.
"Something I learned from a blm guy a while ago, he told me that someone can only block access to blm land legally if they do it and less than two people put in a written complaint in the first year of them blocking it. That goes for road access. I do not know if that is still how it is or not but interesting."
I'm sorry, but the "BLM guy" who told you this is absolutely full of crap. Perhaps in an alternate reality or in "bizzarro world" his theory might be true.
Like Bitterroot says, there must be a legal, established, public easement across the private.