In 1920, Mr. Mather and some of his friends joined in supporting this nature teaching in Yosemite, and Dr. Bryant and Dr. Loye Holmes Miller were employed to lay the foundation of what has continued to be an important part of the program of the Branch of Natural History. A personal letter from Dr. Miller, University of California, Los Angeles, provides a firsthand account of his pioneering in interpretive work in Yosemite: I think John Muir was the first Yosemite guide (see _A Son of the Wilderness_, by L. M. Wolfe). We smaller folk could only strive to emulate. My first experience in the valley involved a six-week period during the summer of 1917 under private auspices. Professor M. L. Maclellan (geology) and I (biology) held a summer school for public school teachers who were largely from Long Beach, California. The work consisted of lectures and field trips about the valley floor and the trails to the rim and to Merced Lake. During the summer of 1919 I was doing similar work at Tahoe when Mr. Stephen T. Mather came through on a flying trip. He asked me to confer with him on the subject of Nature Guide work in Yosemite and urged me to come at once to the valley and begin the work there. It was late in the season and I had spent most of my free time for the year. Furthermore, it seemed to me that there should be some preparation made for the work, including a measure of publicity in the park guidebooks. I therefore urged Mr. Mather to wait until 1920 for the inauguration of an official Nature Guide service. He agreed and we parted with a definite plan for 1920. In the meantime Mr. C. M. Goethe of Sacramento had become interested in the movement and had engaged Dr. H. C. Bryant in a tour of certain summer camps. I also urged the appointment of Dr. Bryant for the Yosemite work in 1920. My University schedule was such that Dr. Bryant was able to report earlier than I. He therefore gave the first official work in the valley. We coöperated in it after my arrival. I knew that I could not devote many summers to the service because of other duties as an officer of the University. Furthermore, it seemed to me that Dr. Bryant was just the man to carry on to a larger field of development. I therefore urged repeatedly that he make a full-time activity of the movement. This end was ultimately realized. Bryant made all the official reports of our work (with my endorsement). Those reports are in the files of the Superintendent’s office in the park. During the month of January, 1921, Dr. Bryant and I gave our services to the cause in an extended lecture tour through the eastern and middle western states. This effort was underwritten personally by Mr. Mather. The purpose and theme in this series was to publicize and stimulate interest in the natural history values of the park and the appreciation of nature through an increased knowledge and understanding.