The Nebraska State Historical Society or any other society whose duty it is to preserve historical sites and monuments may restrict visitation at such hours and times as in its judgment would be a detriment to the site or monument. The society responsible for such site or monument may erect appropriate signs or notices restricting any visitation which might subject the site or monument to hazards and defacing. Any person violating the provisions of such signs or notices shall be guilty of a Class V misdemeanor.