Probably three-fourths of those who thumb through this fat Sierra Club reader (148 articles, 1870-1977) will be among the 175,000 members of the club's 51 branches. But if the early sections have a camp-reunion flavor--tributes to pioneers, memoirs of early High Trips (an annual, month-long hegira of some 200 members and attendants) and internal disputes--even these have the appeal of opening other folks' family albums. And, from founder John Muir's writings to the Exhibit Format books of the 1950s and '60s (created by executive director Dave Brewer), the club has used the written word--plus the photo-images of Ansel Adams, Eliot Porter, etc.--to spread the wilderness-preservation gospel. So here is nature observed in studies of summit butterflies and the ""colors"" (microorganisms) of mountain snow, and discussions of such touchy subjects as ""Too Many Deer"" (over-protected, they exhaust a range just as too many cattle destroy a pasture) and fire-control as the enemy of the once-flourishing sugar pine. Here are accounts of mountain ascents from hand-over-hand scrambles to the advent of ropes and pitons to today's highly technical (unsporting?) climbing feats. Here, too, are the big conservation battles won and lost (Glen Canyon, the redwoods, the Everglades, Tocks Dam) and, beginning in the 1970s, the leading conservation issues--including the minority and labor backlash. A flavorful, energetic, informative aggregation--and when the witnesses are Brewer (on how, in his case, ""the twig was bent"") or Ansel Adams (on photography's role in reducing the importance of size) or Muir himself (on the elderly Emerson's disinclination to brave Yosemite's night air), memorable by any standard.