One of the premier photographers of the 20th century, Ansel Adams is renowned for his black and white photographs of America's national parks, particularly the mountainous American West. His works are eloquently rendered in their use of light, form, and texture. In a career that spanned more than 60 years, Adams became a technical innovator in his field, perfecting the ability to determine the visual and emotional qualities of the finished print even before exposing the negative. He was also one of the original crusaders in the environmental and conservation movements, holding many positions of distinction including Director of the Sierra Club from 1934 to 1971. His works have been exhibited at nearly every major museum, including The Metropolitan Museum of Art, New York, and The Museum of Modern Art, New York, whose Department of Photography he helped found. He was the author of over thirty books and seven portfolios of original prints and was awarded the American Medal of Freedom.