PUBLIC LAW 101-631—NOV. 28, 1990 104 STAT. 4573 utable to any conversion of existing ski area permits into ski area permits pursuant to the National Forest Ski Area Permit Act of 1986 (Public Law 99-522). (c) EXCHANGE AGREEMENTS. —The Secretary shall attempt, within 60 days after the completion of appraisals under this section, to enter into an exchange agreement with Homestake to consummate the exchange of the specific tracts of lands identified in section 2 of this Act. Unless otherwise specified in the exchange agreement, the tracts shall be exchsuiged at the earliest possible date after the exchange agreement is signed. It is the intent of Congress that the exchange be completed no later than two hundred and seventy days after the date of enactment of this Act. (d) ADDITION TO BLACK HILLS NATIONAL FOREST.— Lands acquired by the United States within or adjacent to the exterior boundaries of the Black Hills National Forest shall be added to and administered as part of the Black Hills National Forest. The Secretary of Agriculture is hereby authorized to modify such boundaries to incorporate such lands upon their acquisition by the United States. Upon their inclusion in the National Forest System such lands shall be managed in accordance with the laws, rules and regulations generally applicable to the National Forest System, unless otherwise specifically provided by this Act. (e) DEFINITION.— As used in this Act, the term "Homestake" shall mean the Homestake Mining Company of California or its successors or assigns. SEC. 4. CONVEYANCE TO SUMMIT COUNTY, COLORADO. (a) IN GENERAL.— Upon payment by Summit County to the Secretary of the sum of $25,000 and execution of an agreement between the County and the United States as specified in paragraph (4), the Secretary of Agriculture shall convey to Summit County, Colorado, all right, title and interest of the United States in approximately four hundred and seventy-seven acres of land as generally depicted on a map numbered 7 and entitled "Summit County Landfill", dated July 1990. Such conveyance shall be subject to the following conditions: (1) The lands conveyed shall continue to be used for solid waste disposal, expansion of the Summit County landfill, or other authorized purposes of Summit County government. (2) In the event Summit County ever sells, exchanges or otherwise disposes of all or a portion of the lands acquired pursuant to this section, all proceeds of such sale, exchange, or disposal shall accrue to the United States, or the Secretary of Agriculture may elect to reacquire, without compensation to Summit County, any or all portions of such lands that have not been used for solid waste disposal, as the Secretary determines appropriate prior to their sale, exchange, or disposal by the County. (3) The patent issued by the Secretary of the Interior pursuant to this section shall not contain a reverter provision and under no circumstances shall lands used for solid waste disposal be eligible for reversion to the United States by operation of law after the issuance of such patent. (4) A conveyance pursuant to this section shall be contingent upon the County executing an agreement with the United States prior to such conveyance, the terms of which are acceptable to the Secretary of Agriculture, and that permanently Homestake Mining Company. Wfiste treatment and disposal.