43 CFR 420.23: Public notice and information.

Areas and trails may be marked with appropriate signs to permit, control or prohibit off-road vehicle use on Reclamation lands. All notices concerning the regulation of off-road vehicles shall be posted in a manner that will reasonably bring them to the attention of the public. A copy of any notice shall be made available to the public in the regional office and field offices where appropriate. Such notice, and the reasons therefore, shall be published in the Federal Register together with such other forms of public notice or news release as may be appropriate and necessary to adequately describe the conditions of use and the time periods when the areas involved in an action under these regulations are to be (a) opened to off-road vehicle use, (b) restricted to certain types of off-road vehicle use and (c) closed to off-road vehicle use.