In the early days of the Yellowstone Park it was thought that wolves killed too many elk and were a potential danger to cows and sheep living near the park. In the winter of 1995 after the two-year absence the wolves were brought back to Yellowstone. After that the wolves have repopulated the area and may soon be “delisted” as an endangered species. Far fewer problems have arisen than were predicted, some wolves have been illegally shot oustide the park, have been hit by cars, and occasionally have “gotten into trouble” tracking down domestic livestock, and offense that can lead to the legal death of the wolves involved. Wolves are not normally a danger to humans, unless people habituate them by giving them food, this may lead to aggressive behavior toward humans and can increase the risk of a wolf being poached or hit by a vehicle. The return of wolves has already had beneficial impacts on the Greater Yellowstone Ecosystem. Wolves have preyed on elk, and the carcasses have provided foot to a wide variety of other animals, especially scavenging species. Coyote populations have declined inside wolf territories-a finding that may benefit smaller predators, rodents, and birds of prey. Preliminary data from studies indicate that wolf recovery will likely lead to the greater biodiversity throughout the Greater Yellowstone Ecosystem.