Like his mentor George Melendez Wright, Adolph Murie believed that many long-held assumptions about predators needed to be scientifically tested. Murie, a parks employee, spent years studying Yellowstone’s coyotes to prove that they were important to the park's ecosystem, and not detrimental in the ways they were widely thought to be. Murie’s conclusions went against the grain of the Parks Service; for years, coyotes and wolves in parks across the U.S. had been systematically killed. Murie was ousted from Yellowstone for his findings, and sent to work in more remote parks. But when Murie had the opportunity to study wolves in Alaska, his scientific conclusions about the wolves confirmed his earlier findings about park ecosystems, and eventually resulted in widespread change in how humans treat coyotes and wolves on protected lands.