((a)) ** General authority** Except as provided in subsections (b) and (c) of this section, the Secretary is authorized, consistent with other applicable law in order to carry out the purposes of this Act, to acquire by purchase, donation, exchange, or otherwise any lands within the boundaries of any conservation system unit other than National Forest Wilderness.

((b)) ** Restrictions** Lands located within the boundaries of a conservation system unit which are owned by—

((A)) the State or a political subdivision of the State;

((B)) a Native Corporation or Native Group which has Natives as a majority of its stockholders;

((C)) the actual occupant of a tract, title to the surface estate of which was on, before, or after , conveyed to such occupant pursuant to section 1613(c)(1) and (h)(5) of title 43, unless the Secretary determines that the tract is no longer occupied for the purpose described in section 1613(c)(1) or (h)(5) of title 43 for which the tract was conveyed and that activities on the tract are or will be detrimental to the purposes of the unit in which the tract is located; or

((D)) a spouse or lineal descendant of the actual occupant of a tract described in subparagraph (C), unless the Secretary determines that activities on the tract are or will be detrimental to the purposes of the unit in which the tract is located—

((c)) ** Exchanges** Lands located within the boundaries of a conservation system unit (other than National Forest Wilderness) which are owned by persons or entities other than those described in subsection (b) of this section shall not be acquired by the Secretary without the consent of the owner unless prior to final judgment on the value of the acquired land, the owner, after being offered appropriate land of similar characteristics and like value (if such land is available from public lands located outside the boundaries of any conservation system unit), chooses not to accept the exchange. In identifying public lands for exchange pursuant to this subsection, the Secretary shall consult with the Alaska Land Use Council.

((d)) ** Improved property** No improved property shall be acquired under subsection (a) without the consent of the owner unless the Secretary first determines that such acquisition is necessary to the fulfillment of the purposes of this Act or to the fulfillment of the purposes for which the concerned conservation system unit was established or expanded.

((e)) ** Retained rights** The owner of an improved property on the date of its acquisition, as a condition of such acquisition, may retain for himself, his heirs and assigns, a right of use and occupancy of the improved property for noncommercial residential or recreational purposes, as the case may be, for a definite term of not more than twenty-five years, or in lieu thereof, for a term ending at the death of the owner or the death of his spouse, whichever is later. The owner shall elect the term to be reserved. Unless the property is wholly or partially donated, the Secretary shall pay to the owner the fair market value of the owner’s interest in the property on the date of its acquisition, less the fair market value on that date of the right retained by the owner. A right retained by the owner pursuant to this section shall be subject to termination by the Secretary upon his determination that such right is being exercised in a manner inconsistent with the purposes of this Act, and it shall terminate by operation of law upon notification by the Secretary to the holder of the right of such determination and tendering to him the amount equal to the fair market value of that portion which remains unexpired.

((f)) ** “Improved property” defined** For the purposes of this section, the term “improved property” means—

((1)) a detached single family dwelling, the construction of which was begun before (hereinafter referred to as the “dwelling”), together with the land on which the dwelling is situated to the extent that such land—

((A)) is in the same ownership as the dwelling or is Federal land on which entry was legal and proper, and

((B)) is designated by the Secretary to be necessary for the enjoyment of the dwelling for the sole purpose of noncommercial residential use, together with any structures necessary to the dwelling which are situated on the land so designated, or

((2)) property developed for noncommercial recreational uses, together with any structures accessory thereto which were so used on or before , to the extent that entry onto such property was legal and proper.

((g)) ** Consideration of hardship** The Secretary shall give prompt and careful consideration to any offer made by the owner of any property within a conservation system unit to sell such property, if such owner notifies the Secretary that the continued ownership is causing, or would result in, undue hardship.

((h)) ** Exchange authority**

((1)) Notwithstanding any other provision of law, in acquiring lands for the purposes of this Act, the Secretary is authorized to exchange lands (including lands within conservation system units and within the National Forest System) or interests therein (including Native selection rights) with the corporations organized by the Native Groups, Village Corporations, Regional Corporations, and the Urban Corporations, and other municipalities and corporations or individuals, the State (acting free of the restrictions of section 6(i) of the Alaska Statehood Act), or any Federal agency. Exchanges shall be on the basis of equal value, and either party to the exchange may pay or accept cash in order to equalize the value of the property exchanged, except that if the parties agree to an exchange and the Secretary determines it is in the public interest, such exchanges may be made for other than equal value.

((2)) Nothing in this Act or any other provision of law shall be construed as authorizing the Secretary to convey, by exchange or otherwise, lands or interest in lands within the coastal plain of the Arctic National Wildlife Refuge (other than land validly selected prior to ), without prior approval by Act of Congress.

((i)) ** Donation or exchange**

((1)) The Secretary is authorized to acquire by donation or exchange, lands (A) which are contiguous to any conservation system unit established or expanded by this Act, and (B) which are owned or validly selected by the State of Alaska.

((2)) Any such lands so acquired shall become a part of such conservation system unit.