Dr. David Mattson is a wildlife biologist who now specializes in Grizzly Bears. He is a retired professor from the School of Forestry and Environmental Studies at Yale University and author of numerous studies about Trout and Grizzly Bears in the northern Rockies, including the Demography of Yellowstone Grizzly Bears and Defining Landscapes suitable for the Restoration of Grizzly Bears in Idaho.  With his wife, Louisa Wilcox, he publishes Grizzly Times, an on-line magazine that can be found on the Internet at grizzlytimes.org. In this interview, he talks Grizzly needs and behavior, and about the issue of delisting Grizzly Bears as an Endangered Species and why it is important for them to enlarge their range in the Rockies before delisting should be considered.