There are designations that are available to the U.S. Forest Service that would ban motorized vehicles, any motorized equipment, any man made structure, and that is a "wilderness" designation.
However, public land managed by the BLM is different. This land is owned by the public and the congressional mandate is to provide the land for multiple use.
Unless congress changes its mandate on how public land is to be used, the mandate is multiple use.
I think the problems are that there are no signs marking public and private land, no signs marking the trails, complete lack of law enforcement, fences that were paid for and not erected, and not involving the public interest groups in the decision process regarding roads and trails.