16 U.S. Code § 410hhh–6 - Acquisition of property and boundary adjustments
(a) Acquisition authority
(1) Within the area depicted on the map as the “Acquisition Area” or the national monument, the Secretary may acquire lands and interests therein by purchase, donation, transfer from another Federal agency, or exchange: Provided, That lands or interests therein may only be acquired with the consent of the owner thereof.
(b) Boundary adjustment
As soon as practicable after the acquisition of any land or interest under this section, the Secretary shall modify the boundary of the unit to which the land is transferred pursuant to subsection (b)  of this section to include any land or interest acquired.
(c) Administration of acquired lands
(1) General authority
Upon acquisition of lands under subsection (a) of this section, the Secretary shall, as appropriate—
(A) transfer administrative jurisdiction of the lands to the National Park Service—
(2) Forest service administration
(A) Any lands acquired within the area depicted on the map as being located within Zone B shall be transferred to the Secretary of Agriculture and shall be added to and managed as part of the Rio Grande National Forest.
(B) For the purposes of section 460l–9 of this title, the boundaries of the Rio Grande National Forest, as revised by the transfer of land under paragraph (A), shall be considered to be the boundaries of the national forest.
 So in original. Probably should be “subsection (c)”.