In 1866, Frederick Law Olmsted (the same Olmsted who helped design Central Park, among others) was a member of the commission entrusted with managing the Yosemite Grant. He wrote a lengthy report about Yosemite, which today serves as a sort of ignored prophecy:

The first point to be kept in mind then is the preservation and maintenance as exactly as is possible of the natural scenery; the restriction, that is to say, within the narrowest limits consistent with the necessary accommodation of visitors, of all artificial constructions and the prevention of all constructions markedly inharmonious with the scenery or which would unnecessarily obscure, distort or detract from the dignity of the scenery.

In addition to the more immediate and obvious arrangements by which this duty is enforced, there are two considerations which should not escape attention.

First; the value of the district in its present condition as a museum of natural science and the danger — indeed the certainty — that without care many of the species of plants now flourishing upon it will be lost and many interesting objects be defaced or obscured if not destroyed….

Second; it is important that it should be remembered that in permitting the sacrifice of anything that would be of the slightest value to future visitors to the convenience, bad taste, playfulness, carelessness, or wanton destructiveness of present visitors, we probably yield in each case the interest of uncounted millions to the selfishness of a few individuals… It is but sixteen years since the Yosemite was first seen by a white man, several visitors have since made a journey of several thousand miles at large cost to see it, and notwithstanding the difficulties which now interpose, hundreds resort to it annually. Before many years, if proper facilities are offered, these hundreds will become thousands and in a century the whole number of visitors will be counted by millions. An injury to the scenery so slight that it may be unheeded by any visitor now, will be one multiplied by these millions. But again, the slight harm which the few hundred visitors of this year might do, if no care were taken to prevent it, would not be slight, if it should be repeated by millions. At some time, therefore, laws to prevent an unjust use by individuals of that which is not individual but public property, must be made and rigidly enforced. The principle of justice involved is the same now that it will be then; such laws as this principle demands will be more easily enforced, and there will be less hardship in their action, if the abuses they are designed to prevent are never allowed to become customary but are checked while they are yet of unimportant consequence. It should, then, be made the duty of the Commission to prevent a wanton or careless disregard on the part of anyone entering the Yosemite or the Grove, of the rights of posterity as well as of contemporary visitors, and the Commission should be clothed with proper authority and given the necessary means for this purpose.

This duty of preservation is the first which falls upon the State under the Act of Congress, because the millions who are hereafter to benefit by the Act have the largest interest in it, and the largest interest should be first and most strenuously guarded.

For the first time since 1996, Yosemite received over four million visitors this past year. Enough said.

(You can read the full 1866 report at