16 U.S.C. § 460s-7
The Secretary is authorized, subject to the limitations, conditions, and restrictions imposed by this subchapter, to acquire the land, water, and other property, and improvements thereon, and any interests therein (including easements) within the boundary described in section 460s-1 of this title by donation, purchase with donated or appropriated funds, transfer from any Federal agency, exchange, or condemnation; except that such authority to acquire by condemnation shall be exercised only in the manner and to the extent specifically authorized in this subchapter.
In exercising his authority to acquire property under this subchapter, the Secretary shall give immediate and careful consideration to any offer made by an individual owning property within the lakeshore to sell such property to the Secretary. In considering any such offer, the Secretary shall take into consideration any hardship to the owner which might result from any undue delay in acquiring his property.
Any property or interests therein, owned by the State of Michigan, or any political subdivisions thereof, may be acquired only by donation. Notwithstanding any other provision of law, any Federal property located within such area may, with the concurrence of the agency having custody thereof, be transferred without consideration to the administrative jurisdiction of the Secretary for use by him in carrying out the provisions of this subchapter.
The Secretary shall make every reasonable effort to acquire property through negotiation and purchase. Where agreement is not reached and condemnation proceedings are filed, the owner of such property shall be paid the fair market value thereof as determined in such proceedings.
Nothing in this subchapter shall be construed to prohibit the use of condemnation as a means of acquiring a clear and marketable title, free of any and all encumbrances.
In exercising his authority to acquire property by exchange the Secretary may accept title to any non-Federal property within the area designated by section 460s-1 of this title for inclusion in the lakeshore, and in exchange therefor he may convey to the grantor of such property any federally owned property under his jurisdiction within the State of Michigan which he classifies as suitable for exchange or other disposal. The values of the properties so exchanged either shall be approximately equal or, if they are not approximately equal, the values shall be equalized by the payment of cash to the grantor or to the Secretary as the circumstances require.
16 U.S.C. § 460s-7