Olaus Johan Murie (1889-1963), was known as the "father of modern elk management." As a naturalist, author, and wildlife biologist, he did groundbreaking field research on a variety of large northern mammals. Dr. Mark Elbroch is author and coauthor of several guides to natural history. He is currently the Science Director of Panthera's Jaguar and Puma Programs. He earned his doctoral degree while leading cougar projects in Southern Chile and the United States. ROGER TORY PETERSON, one of the world's greatest naturalists, received every major award for ornithology, natural science, and conservation as well as numerous honorary degrees, medals, and citations, including the Presidential Medal of Freedom. The Peterson Identification System has been called the greatest invention since binoculars.