2010 - present

April 29, 2013, Bill McKibben, environmental activist and founder of the grassroots climate campaign 350.org. "350: The Most Important Number in the World".

February 7, 2012 - Jon Marvel, Executive Director of Western Watersheds Project. "The Western Paradox: Public Lands, Dependent States and Speaking for the Earth." 

September 27, 2010 - Adam Sowards, Associate Professor of History at the University of Idaho. "The Environmental Justice: William O. Douglas and American Conservation. "April 22, 2010 - Graham Chisholm - Executive Director of Audubon California. "Earth Day at Forty: New Conservation Challenges for the 21st Century."

2000 - 2009

October 18, 2007 - William deBuys, acclaimed author. "Uncle Aldo (Leopold): Learning to Learn about the Natural World. "October 19, 2006 - Nadine Strossen, President of the American Civil Liberties Union (ACLU). "Abuse of Power: The Assault on Civil Liberties After 9/11."

September 20, 2005 - David Quammen, writer. "The Gentle Mr. Darwin: Why So Many Americans Fear Him, and Why They Should."April 12, 2005 - William F. Schulz, Executive Director of Amnesty International USA ."Tainted Legacy: 9/11 and the Ruin of Human Rights. "September 18, 2003 - Nils D. Christoffersen, Field Program Manager, Wallowa Resources. "Conservation in the 21st Century: Connecting the Global to the Local. "September 24, 2002 - Sister Helen Prejean, Author of the International Best-Selling Book "Dean Man Walking." (co-sponsored by President's Office).October 16, 2001 - Morris Dees, Co-founder of the Southern Poverty Law Center (co-sponsored by President's Office). "Hope and Tolerance in the New Millennium."

September 25, 2000 - R. McGreggor Cawley, Professor of Political Science, University of Wyoming. "The Voice of the Inanimate Object, Thoughts on the Politics of Wilderness."April 4, 2000 - Judith Butler, Department of Rhetoric and Comparative Literature at the University of California-Berkeley. "On the Value of Being Disturbed" (discussed recent controversy surrounding an exhibit at the Brooklyn Museum of Ar)t.

1996 - 1999

Sept. 25-26, 1998 - Featured speakers: David J. Danelski, Stanford University; Lucas A. Powe, Jr., The University of Texas; Philippa Strum, City University of New York-Brooklyn College and the Graduate Center; Melvin I. Urofsky, Virginia Commonwealth University. "William O. Douglas Centennial Symposium: Enduring Free Speech Controversies and the Legacy of William O. Douglas, '20."April 6, 1998 - Roger K. Newman, Research Scholar, New York University School of Law. "William O. Douglas: How He Speaks to Us Today." April 28, 1997 - Nadine Strossen, Professor of Law, New York Law School, and national president of the American Civil Liberties Union. "Defending Pornography: Free Speech, Sex, and the Fight for Women's Rights." April 22, 1996 - Victor M. Sher, President, Sierra Club Legal Defense Fund, Inc. "Environmental Rights and Civil Justice: The Judicial Legacy of William O. Douglas."