Then, in December 1969, after many months of sometimes bitter in-fighting, David Brower was fired as Executive Director, to be replaced by Michael McCloskey, former Northwest Conservation Representative of the Club and graduate of the University of Oregon Law School.

Strangely, Brower’s departure triggered a renewed vigor among Club leaders who were determined not to lose ground in their quest for a quality environment. That the Club did not falter at this traumatic juncture in its history is a tribute to the strong and effective volunteer leadership nurtured by its unique grass roots structure. From this episode forward the Club appears to drop the last shreds of its parochialism and to embrace (though not without some misgivings) its full responsibility as a national (some would insist, international) conservation organization. On the other hand, there can be no question that Brower’s genius for innovation (one thinks immediately of the Exhibit Format books and full-page advertisements) gained national prominence for the Club and set the stage for its phenomenal growth in the Sixties. The Club itself recognized this contribution by bestowing upon Brower its highest honor in 1977 — the John Muir Award.

— Edward B. Brazee, Index to the Sierra Club Bulletin 1950−1976 Volumes 35−61, Oregon State University Press, 1978 (via)