Thomas D. Mangelsen is considered one of the foremost living nature photographers in the world. Mangelsen has been a champion of conserving the Greater Yellowstone Ecosystem and giving voice to its unparalleled wildlife for decades. Todd Wilkinson is western correspondent for National Geographic and the Guardian, as well as the author of several acclaimed books and a contributor to Yellowstone: A Journey Through America's Wild Heart. Jane Goodall, known for her landmark chimpanzee study, is the most recognizable figure in conservation today. Yellowstone Forever is the official nonprofit partner of Yellowstone National Park.