The notes provide a detailed listing and evaluation of the major works used in this study. The following discusses briefly sources of importance for further research.

Manuscript collections of national park history are numerous. Accordingly, scholars will want to consult a superb new bibliography, Richard C. Davis, North American Forest History: A Guide to Archives and Manuscripts in the United States and Canada (Santa Barbara, Calif.: Forest History Society, Inc. and Clio Books, 1977). Its title is misleading; in fact all areas of conservation, not just forests, are well covered. Listed, for example, are the collections consulted for this study, including the William E. Colby, Francis P. Farquhar, Robert Underwood Johnson, John Muir, Robert Bradford Marshall, and Sierra Club records in the Bancroft Library at the University of California, Berkeley. The Library of Congress provided other valuable manuscripts, among them the Frederick Law Olmsted and John C. Merriam papers. The J. Horace McFarland collection, located in the archives building of the Pennsylvania Museum and Historical Commission, Harrisburg, proved especially important for its coverage of the decade preceding formation of the National Park Service. By far the most voluminous repository of primary materials is Record Group 79, the Records of the National Park Service maintained by the National Archives in Washington, D.C. Considering its size, R. G. 79 is well catalogued and relatively easy to use. Regional headquarters of the National Park Service are custodians of most documents produced since 1949; similarly, many of the larger parks, including Yosemite and Yellowstone, have libraries and holdings of their own. Finally, specialty departments, most notably the Conservation Library Center of the Denver Public Library, are acquiring private papers on environmental history subjects.

Printed government documents are another important source for national park history. In addition to the House and Senate debates published in the Congressional Globe and Congressional Record, there are the standard reports on bills, hearings before congressional committees, and similar documents, usually printed in conjunction with establishment of the parks. Testimony pertaining to the Jackson Hole and Redwood National Park controversies, for example, is exhaustive. Major branches of the federal government, including the Interior Department and National Park Service, until recently published the annual reports of the secretary and director respectively. This work draws heavily on each of these sources, as well as Statutes at Large for wording of park legislation as finally approved.

No examination of national park history is complete without extensive use of the primary source materials also to be found in major newspapers, periodicals, and conservation journals. Poole's Index and Reader's Guide list hundreds of relevant articles; researchers should be aware, however, that many popular magazines and specialty journals, among them National Parks Magazine and American Forests and Forest Life, were not always indexed during their initial years of publication. Indeed, until early 1978 the Sierra Club Bulletin was ignored by Reader's Guide. For maximum coverage, therefore, collections of the more important journals should be examined off the shelf. Although exhausting, the procedure often yields unexpected dividends, including period advertisements and letters-to-the-editor columns.

For secondary literature there is another excellent guide, Ronald J. Fahl, North American Forest and Conservation History: A Bibliography (Santa Barbara, Calif.: Forest History Society, Inc. and A. B. C.—Clio Press, 1977). As a legislative and administrative history of the national parks to 1960, John Ise, Our National Park Policy: A Critical History (Baltimore: Johns Hopkins University Press, 1961), is definitive. The value of the study is diminished, nevertheless, by the haphazard use and occasional inaccuracy of its footnotes. Similarly, Ise chose to discuss the parks individually rather than collectively in most instances. As one result, little attention is paid to the formation of the national park idea itself, especially the intellectual and nationalistic trends prior to the establishment of Yosemite (1864) and Yellowstone (1872). Leo Marx, The Machine in the Garden: Technology and the Pastoral Ideal in America (New York: Oxford University Press, 1964); Roderick Nash, Wilderness and the American Mind (New Haven: Yale University Press, 1967); and Hans Huth, Nature and the American: Three Centuries of Changing Attitudes (Berkeley and Los Angeles: University of California Press, 1957), are among the more important studies dealing with early perceptions of the environment in general.

Two biographies, Robert Shankland, Steve Mather of the National Parks, 3d ed. (New York: Alfred A. Knopf, 1970), and Donald C. Swain, Wilderness Defender: Horace M. Albright and Conservation (Chicago: University of Chicago Press, 1970), are excellent for the formative years of the National Park Service. Individual histories of the national parks are usually less interpretive or complete. Exceptions include Richard A. Bartlett, Nature's Yellowstone (Albuquerque: University of New Mexico Press, 1974), and Douglas H. Strong, A History of Sequoia National Park (Ph D. dissertation, Syracuse University, 1964). A model popular treatment of a national park is Ann and Myron Sutton, Yellowstone: A Century of the Wilderness Idea (New York: Macmillan Co. and the Yellowstone Library and Museum Association, 1972). Harley E. Jolley, The Blue Ridge Parkway (Knoxville: University of Tennessee Press, 1969), gives insights into the origins of the national park system's most famous roadway.

Emerging themes in national park history are suggested by essays such as Peter Marcuse, "Is the National Parks Movement Anti-Urban?" Parks and Recreation 6 (July 1971): 17-21, 48; and Darwin Lambert, "We Can Have Wilderness Wherever We Choose," National Wildlife 11 (August-September 1973): 20-24. A recent treatment of traditional ruptures in the conservation movement is Elmo R. Richardson's Dams, Parks, and Politics: Resource Development and Preservation in the Truman-Eisenhower Era (Lexington: University of Kentucky Press, 1973). For the Progressive period and its aftermath, there is Richardson's The Politics of Conservation: Crusades and Controversies, 1897-1913 (Berkeley and Los Angeles: University of California Press, 1962); Samuel P. Hays, Conservation and the Gospel of Efficiency: The Progressive Conservation Movement, 1890-1920 (Cambridge, Mass.: Harvard University Press, 1959); and Donald C. Swain, Federal Conservation Policy, 1921-1933 (Berkeley and Los Angeles: University of California Press, 1963). John F. Reiger, in American Sportsmen and the Origins of Conservation (New York: Winchester Press, 1975), invites further debate with his thesis that responsible hunters and fishermen, not preservationists in the traditional sense, launched conservation on all fronts during the second half of the nineteenth century.

Although major professional journals are beginning to recognize the appropriateness of environmental history, the Journal of Forest History promises to remain the standard in the field on the basis of its exhaustive updating of all manuscript collections and scholarly articles. In a more contemporary vein, National Parks and Conservation Magazine: The Environmental Journal, Audubon, and the Sierra Club Bulletin, among others, are vital for maintaining contact with current issues which themselves will someday be history.