David Bedan graduated from Bellarmine University with a B.A. in biology in 1958. He did graduate work in bacteriology and microbiology at Indiana University. After serving four years in the U.S. Air Force, David completed his Masters and Ph.D in Philosophy from the University of Notre Dame.

David was the Director of St. Louis University's Institute of Environmental Studies for 5 years, and served on the faculty for eight years. After leaving St. Louis University, David was hired at Missouri department of Resources (MoDNR) from 1978-1997 in the Division of Parks, the Director's Office, the Division of Energy of Environmental Quality and the Division of Energy. David retired in 1997.

David is active in several Missouri organizations, including the Ozark Chapter of the Sierra Club, the Missouri Coalition for the Environment, the St. Louis Open Space Council, the Missouri Waste Control Coalition, and the Audubon Society (River Bluffs Chapter, Columbia Chapter, Missouri Audubon Council, Audubon Society of Missouri and Audubon Missouri).