2011 US Code
Title 16 - Conservation
Chapter 1 - NATIONAL PARKS, MILITARY PARKS, MONUMENTS, AND SEASHORES (§§ 1 - 460zzz-7)
Subchapter III - NATIONAL PARK FOUNDATION (§§ 19 - 19o)
Section 19g - Gifts, devises, or bequests; restriction; real property interests; property with encumbrances...

The Foundation is authorized to accept, receive, solicit, hold, administer, and use any gifts, devises, or bequests, either absolutely or in trust of real or personal property or any income therefrom or other interest therein for the benefit of or in connection with, the National Park Service, its activities, or its services: Provided, That the Foundation may not accept any such gift, devise, or bequest which entails any expenditure other than from the resources of the Foundation. An interest in the real property includes, among other things, easements or other rights for preservation, conservation, protection, or enhancement by and for the public of natural, scenic, historic, scientific, educational, inspirational, or recreational resources. A gift, devise, or bequest may be accepted by the Foundation even though it is encumbered, restricted, or subject to beneficial interests of private persons if any current or future interest therein is for the benefit of the National Park Service, its activities, or its services.

(Pub. L. 90–209, §3, Dec. 18, 1967, 81 Stat. 656.)