Many many years ago in Alpine County CA. we went up this road where we knew Deer were mi9grating out of the high country. Got there but there was a gate blocking it. We checked our forest service maps and sure as heck it was blocking a public access road. We went back to the little local grocery store and talked to the owner about it and how we were going to open it up. He was a nice guy and advised us not to do it as the locals put the gate up to keep outsiders out of the prime area. He also said the sheriff would give us a bad time and being elected he did what the locals wanted he to do. So we went to the nearest forest service office and complained and they just shucked us off. To my knowledge, that gate is still up today.
Of established National Forest Service roads, that were actually designated roads, I have seen far, far many more closed to public access by the National Forest Service themselves, than all other reasons combined.
The greenies they have running the place now don't want you in "their national forest land"............ OR the ranchers either, for that matter.
