Born in Los Angeles, California, 1947. Currently lives in Los Angeles. Ketchum's most recent publications include The Hudson River and the Highlands (1985), The Tongass: Alaska's Vanishing Rainforest (1987), and Overlooked in America: The Success and Failure of Federal Land Management (1991). He received the Ansel Adams Award for Conservation Photography from the Sierra Club in 1989.
Merry A. Foresta, Stephen Jay Gould, and Karal Ann Marling Between Home and Heaven: Contemporary American Landscape Photography (Washington, D.C. and Albuquerque, New Mexico: The National Museum of American Art in association with the University of New Mexico Press, 1992)