Getting back to the National Park Service.
The National Park Service was created by the Sixty-Fourth Congress on August 25, 1916 by Public Law 64-235. Pdf Link
The purpose of the National Parks Service is stated in the legislation as follows:
The service thus established shall promote and regulate the use of the Federal areas known as national parks, monuments, and reservations hereinafter specified by such means and measures as conform to the fundamental purpose of the said parks, monuments, and reservations, which purpose is 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.
continuing . . .
He (Secretary of the Interior) may also grant privileges, leases, and permits for the use of land for the accommodation of visitors in the various parks, monuments, or other reservations herein provided for, but for periods not exceeding twenty years; and no natural curiosities, wonders, or objects of interest shall be leased, rented, or granted to anyone on such terms as to interfere with free access to them by the public:
Unless you are over 102 years old, you are one of the future generations that congress set aside the assets of the National Parks for your free access of enjoyment.
Let me start with, who are the true owners of the National Parks? "We the People". Collectively the American People have the property rights to the public land. We own it.
The government employees manage the public lands for "We the People". They work for us for an expressed purpose.
The mandate for the National Park Service is clearly to protect the natural and historic objects, the wild life, and conserve the scenery. And the purpose of the protection of these assets is for the public and future generations’ enjoyment.
Interestingly the last quoted paragraph clearly states the Secretary of the Interior has the authority “to grant privileges, leases, and permits for the use of land” as long as they do not "interfere with free access to them by the public"
Clearly in the founding legislation of the National Parks Service there are no "Exclusive Permits" limiting free park access to the public and the enjoyment thereof.