Born in Wilmington, Delaware, 1944. Currently lives in New York City. Mortenson's work was included in "The New Pastoral," International Museum of Photography at George Eastman House, Rochester, New York (1990). A monograph of his work, Meadowland, was published in 1983 (Listrum Press).
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)