Provided, however, That under conditions where it is found that significant adverse impact on park resources, wildlife populations or visitor enjoyment of resources will result, the Superintendent shall prohibit the gathering, or otherwise restrict the collecting of these items. Portions of a park area in which restrictions apply shall be designated on a map which shall be available for public inspection at the office of the Superintendent, or by the posting of appropriate signs, or both.
36 C.F.R. §7.86