The mighty Colorado River through Glen Canyon, in southeastern Utah, carved out the West's most sublime river landscape. In 1963, as the gates closed on Glen Canyon Dam, Lake Powell began to inundate this mysterious setting, but not before two photographers recorded its wonders -- Eliot Porter, who made the Glen famous in The Place No One Knew, and Tad Nichols, the man who first led Porter through the canyon. In more than thirty river trips beginning in the early 1950s, Nichols created thousands of images of the place that gave birth to the modern environmental movement.