If you were to saunter through the spruce-scented church of American environmentalism, looking upon the portraits of its saints, you’d first see John Muir, father of the Sierra Club, defender of the Yosemite, a green Abraham with a mossy old-man’s beard. Next to him, his camping companion, Teddy Roosevelt, protector of nearly 230 million acres of land. You’d find Aldo Leopold, whose A Sand County Almanac (1949) has become a sacred text. David Brower, whom John McPhee called “the sacramentarian of ecologia americana, the Archdruid himself,” director of Muir’s Sierra Club and founder of both