In the 1920's the thirsty city of San Francisco reached deep into Yosemite National Park to build the O'Shaughnessy Dam on the Tuolumne River, diverting one-third of the river's water and flooding the Hetch Hetchy Valley, said at the time to be as magnificent as Yosemite Valley itself. Brower envisages the species-by-species reclamation of the valley by its native flora and fauna as wildness flourishes again. Offering viable alternatives for restoration, Brower's Hetch Hetchy is both an exploration of the pitched battle over an environmental tragedy and an inspiring reverie of a possible future.