All camping, picnicking, use of alcoholic beverages, setting or use of fires, use of the sites for cleaning of fish, the deposit of any garbage, paper, cans, bottles, or rubbish of any kind, or use of the sites for any commercial activity (including commercial purchase of fish) shall be subject to such prohibitions, restrictions, or other regulations as the Regional Director may prescribe and cause to be posted on the site or sites to which said regulations are applicable; provided that no fee may be charged to any Indian or member of his family for any such use.