The Secretary of the Interior and the Secretary of Agriculture are authorized and directed, within two years after June 24, 1954, to exchange administrative jurisdiction of revested Oregon and California Railroad grant lands lying within the boundaries of any national forest or within two miles of such boundaries, and national-forest lands of approximately equal aggregate value, when by such exchange the administration of the lands will be facilitated. Such exchanges shall be made subject to outstanding contracts, permits or other existing rights: Provided, That the said national-forest lands, administrative jurisdiction of which is transferred to the Secretary of the Interior, shall be excluded from the national forest and shall become subject to administration under the same provisions of law as the revested lands in exchange for which they were transferred, and the revested lands, administrative jurisdiction of which is transferred to the Secretary of Agriculture, shall become a part of the national forests subject to administration under the laws applicable to national forests: Provided further, That subject to the requirement of approximate equal aggregate value for the overall exchange, the revested lands and the national-forest lands, administrative jurisdiction of which is exchanged in any county, shall be approximately equal in area unless otherwise agreed to by the counties concerned. The exchanges provided for in this section shall in each case be evidenced by an order signed by the Secretary of the Interior and the Secretary of Agriculture and such orders shall be transmitted to the Division of the Federal Register for filing and publication.