16 U.S.C. 1.1.1 - Creates the Park Service

With a fundamental purpose to preserve, protect, and defend the shrubbery, for ourselves and our posterity.

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"There is created in the Department of the Interior a service to be called the National Park Service … [which] shall ... regulate the use of the … national parks … by such … measures as conform to the fundamental purpose of the said parks …  [;namely,]  to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations. [link to 16 U.S.C. 1.1.1]

And provide "photo opportunities"