Lake George, in upstate New York, where Alfred Stieglitz owned a vacation retreat, inspired numerous photographs, including his “equivalent” series of cloud studies begun in 1922. Stieglitz liked photographing ephemeral natural phenomena, particularly for the challenge of balancing tonal variations of light and dark among the sky, clouds, and, in this case, the thin sliver of the horizon. Formally, these explorations of abstraction and pattern resulted in photographs that paralleled works by Georgia O’Keeffe, Marsden Hartley, Arthur Dove, and other American modernists. But Stieglitz, mindful that an image need not necessarily correspond to its subject, also likened his “equivalent” cloud photographs to music or emotions.