If under applicable law the Secretary concerned decides to transfer out of Federal ownership any lands covered in whole or in part by a right-of-way, including a right-of-way granted under the Act of (; ), the lands may be conveyed subject to the right-of-way; however, if the Secretary concerned determines that retention of Federal control over the right-of-way is necessary to assure that the purposes of this subchapter will be carried out, the terms and conditions of the right-of-way complied with, or the lands protected, he shall (a) reserve to the United States that portion of the lands which lies within the boundaries of the right-of-way, or (b) convey the lands, including that portion within the boundaries of the right-of-way, subject to the right-of-way and reserving to the United States the right to enforce all or any of the terms and conditions of the right-of-way, including the right to renew it or extend it upon its termination and to collect rents.87 Stat. 57630 U.S.C. 185November 16, 19731973-11-16