The lands within the recreation area, subject to valid existing rights, are hereby withdrawn from location, entry, and patent under the United States mining laws. The Secretary of the Interior, under such regulations as he deems appropriate, may permit the removal of the nonleasable minerals from lands or interests in lands under his jurisdiction within the recreation area in the manner prescribed by section 387 of title 43, and from those under the jurisdiction of the Secretary of Agriculture within the recreation area in accordance with the provisions of section 192c of title 30, and he may permit the removal of leasable minerals from lands or interests in lands within the recreation area in accordance with the Mineral Leasing Act of February 25, 1920, as amended [30 U.S.C. 181 et seq.], or the Acquired Lands Mineral Leasing Act of August 7, 1947 [30 U.S.C. 351 et seq.], if he finds that such disposition would not have significant adverse effects on the purposes of the Central Valley project or the administration of the recreation area: Provided