One hundred fourteen years have elapsed since the explorers in Joseph Walker’s party first made their way to some point on the north rim of Yosemite Valley and beheld a tremendous scene beneath them. It is to be hoped that the Yosemite visitor today will have his enjoyment of Yosemite National Park somehow enhanced by the recorded story of the human events during the past century, particularly by the story of the human effort that made Yosemite accessible to him, but not too accessible. Yosemite, like other national parks, has its master plan. Upon it is set down in rather definite form the conception of the park staff of needs for physical improvements. This prescription is reviewed by technicians and executives in central offices and made to delimit the maximum development necessary to meet the requirements of staff and public. The master plan also contains an analysis of the inspirational and recreational experiences which attract the multitude of visitors to the park. As might be expected this analysis of Yosemite’s offerings points to the fact that one of the notable values of the reservation is found in its capacity to stimulate pride in and understanding of the heritage of natural beauty preserved within the park’s boundaries. Another important value is indicated in the capacity of the park to serve as a repository of scientific treasures. In this last-named role as “museum of the out-of-doors,” Yosemite National Park reasonably may be expected to become increasingly important as the less protected areas of the Sierra Nevada are more and more encroached upon by exploiters. The exploiters are not always concerned with livestock, minerals, or timber. The aggressiveness of those who cater to recreation seekers—even of the recreation seekers themselves—constitutes a force to be reckoned with, and this group particularly lays siege to the structure of National Park Service conservatism. It is well that the visitor to this and other national parks extend his ken. We know something of what has happened since 1833. But what will have happened to the Yosemite region by the year 2033 A.D., two hundred years after white man’s first glimpse of the valley? Will the men of great enterprise have built “ladders touching the sky, changing the face of the universe and the very color of the stars?” Or will there still be a remnant of mountain sanctuary, where the handiwork of today’s and tomorrow’s visitors will be as hard to discern as Joe Walker’s footsteps are to trace? [Illustration: Big tree] _CHRONOLOGY_ The following outline of the history of the Yosemite region cites the original sources of information used in preparing this book. References are to the pages of publications and manuscripts appearing in the bibliography which follows. Items cited frequently are abbreviated: