_A host of friends and associates have contributed to the production of the book. Great thanks are due my wife for her generous help and continuous encouragement. Mrs. H. J. Taylor lent important assistance and advice. Among the Yosemite staff members who gave valuable help, former Park Naturalists_ _C. A. Harwell and C. Frank Brockman and former museum-secretary, Mrs. William Godfrey, made especially important contributions; however, the extraordinary interest of every member of the park naturalist staff has placed me in the debt of the entire organization. The American Association of Museums, in addition to coöperating with the National Park Service in founding the Yosemite Museum, has contributed directly to the production of this book by assisting me in the collecting of rare publications and helping, generally, in assembling Yosemite data. The Yosemite Park and Curry Company has made available many publications and photographs. Mrs. Don Tresidder of that organization, particularly, has given material assistance in establishing dates and historical facts. The Sierra Club has permitted the use of my article, “Mining Excitements East of Yosemite,” which was first published in the _Sierra Club Bulletin_. To David R. Brower, Editor of the _Sierra Club Bulletin_ and at the University of California Press, I acknowledge particular indebtedness, not only for editorial guidance in producing the book but, also, for his historian’s sense and his basic knowledge of the Yosemite terrain and its story. Some of his contributions to the content of the text are acknowledged elsewhere, but his friendly help has extended to every part of the book. Francis P. Farquhar and Ansel F. Hall, during a quarter of a century of our friendships, have given assistance and encouragement. Mr. Farquhar has read parts of the manuscript and made helpful suggestions. His library has been drawn upon in the course of my work. The more recent photographs reproduced upon the following pages are credited to their makers, to each of whom I am deeply beholden. For use of the very old pictures used herein, I am indebted to the Yosemite Museum, and to Superintendent Frank Kittredge I express thanks for this and many other helpful acts performed by him and his staff members in furthering my efforts._