Nothing contained in this subchapter shall restrict the acquisition, granting or use of permits or rights of way within grazing districts under existing law; or ingress or egress over the public lands in such districts for all proper and lawful purposes; and nothing contained in this subchapter shall restrict prospecting, locating, developing, mining, entering, leasing, or patenting the mineral resources of such districts under law applicable thereto.
43 U.S.C. § 315e