Gray Wolves (often called timber wolves) are carnivorous canines who live in the wilds of North America and Eurasia. Research has shown that increased wolf numbers have significant positive effects on wild environments. The wolves accomplish this by: 1) preening prey animal populations of diseased, weak, and old individuals, creating stronger, healthier herds; 2) altering grazing behavior of prey animals producing re-vegetated stream and river banks; 3) preventing overpopulation of smaller predators, like coyotes, which revitalizes populations of pronghorns, fox, and other smaller prey animals; and 4) providing more carrion for bears, eagles, and other scavengers.

Before the European invasion of North America, hundreds of thousands of wolves roamed the continent. Humans aggressively slaughtered wolves to the point that by the early 1930s, almost all the wolves in the United States had been killed, primarily by bounty hunters, with only tiny, isolated clusters of wolves surviving along the Canadian border.