43 CFR §423.63

Areas where rules were in effect on April 17, 2006, that differ from the rules set forth in subpart C of this part are considered existing special use areas, and such differing rules remain in effect to the extent allowed by subpart A of this part, and to the extent they are consistent with § 423.28(a). For those existing special use areas, compliance with §§ 423.60 through 423.62 is not required until the rules applicable in those special use areas are modified or terminated.