When Lewis and Clark crossed Montana in the early 1800s, gray wolves (Canis lupus) were commonly seen on the plains, and were, along with grizzly bears (also originally a prairie animal), the dominant predator of the plains wilderness ecosystem. But with the advent of the fur trade, and then agriculture based on livestock, the native wolf populations were gradually exterminated. By the 1930s, no gray wolves remained in Montana.

The rise of environmentalism and the passage of the Endangered Species Act (ESA) in 1973 created a new atmosphere of advocacy for reintroducing the wolf to the Western United States. Organizations including Defenders of Wildlife and the National Wildlife Federation spearheaded a successful effort to have wolves listed as “endangered” under the ESA’s provisions. “Bounty” programs, which paid hunters to kill wolves, were discontinued, and it became illegal to kill wolves in the United States. In addition, provisions of the ESA called on the federal government to implement a plan for the recovery of the gray wolf population.

In the early 1980s, wolves from Canada began to move into northwest Montana, and by 1995 there were six wolf packs in that region. Advocates for wolves proposed boosting the recovery of wolf populations by actively restoring wolves to suitable areas in the Northern Rockies. Objections arose from livestock ranchers, hunters worried about the impact of wolves on game populations, and other concerned people, while environmentalists and wildlife advocates cheered on the reintroduction.

Eventually, the U.S. Congress held hearings and ultimately ordered the U.S. Fish and Wildlife Service (USFWS) to prepare an Environmental Impact Statement on the reintroduction of wolves to Yellowstone National Park and central Idaho. In 1995 and 1996, as part of its wolf recovery plan, the USFWS trapped 66 wolves in southwestern Canada and transplanted them to Yellowstone National Park and central Idaho.

The wolves quickly made themselves at home, reproducing and expanding their range faster than any of the experts had predicted.

One major objection to the reintroduction of wolves to the West was that wolves would devastate livestock herds. Even fans of reintroducing wolves acknowledged that wolves are highly efficient predators. To help address this concern, Defenders of Wildlife launched a program to compensate livestock producers when the reintroduced wolves preyed on their stock. By the end of 2002 the fund had paid out more than $270,000 to ranchers in the Northern Rockies.

In general, predation on livestock has been lower than predicted when the wolf reintroduction was first proposed, though it has still been significant. Fifty-two cattle, 99 sheep, nine dogs, and five llamas were confirmed lost to wolves in 2002 (these figures do not include livestock killed by predators but not conclusively confirmed as wolf kills). In those areas of Montana where Yellowstone wolves have dispersed, seven of 10 known wolf packs were involved in livestock depredation in 2002, and confirmed losses included 10 cattle and 71 sheep killed. Many wolves have been killed by the USFWS when it has been impossible to deter them from further predation.

By the mid-2000s, approximately 900 to 1,250 wolves were living in the northern Rockies in about 100 packs. While most of the population was in the Yellowstone Park area, some packs and individuals—the archetypal lone wolf—dispersed across other parts of Montana.

Beginning in 2005, ranchers in remote Garfield and McCone counties, which are adjacent to the vast C. M. Russell Wildlife Refuge (more than 300 miles north of Yellowstone, along the Missouri River), began to relate stories of abnormally high numbers of sheep and calves killed by predators, accompanied by sightings of canines that were described as wolves. The numbers of animals killed—by 2006 the tally included hundreds of sheep, dozens of young cattle, and even colts—convinced many ranchers that they were dealing with a wolf. According to USFWS regulations, individual ranchers are not allowed to kill a predatory wolf. Eliminating a predatory wolf falls to authorized USFWS agents.

In fall 2006 a large 105-pound male wolf was shot by USFWS hunters between Jordan and Circle—the first wolf seen in the area since the 1920s. The wolf was held responsible for the deaths of livestock worth tens of thousands of dollars. Under terms of the original reintroduction program, these ranchers were due reimbursement for the value of the livestock killed by the wolf—if the livestock-killing wolf was part of the reintroduced wolf population from Yellowstone.

The DNA of each of the reintroduced wolves from Yellowstone was on record, and after performing a DNA test on the wolf killed by the USFWS, researchers found that it was not part of the reintroduced population, but rather a wolf whose DNA matched wolves from northern Minnesota. Apparently the wolf had followed the Missouri River west from the woodlands of Minnesota before making its home in the Missouri badlands. Because the wolf was not part of the reintroduced population, affected ranchers were not able to apply for reimbursement for their dead livestock. The incidence of wolf sightings and heavy predation continues in eastern Montana; it is thought likely that wolves have set up a breeding population in the C. M. Russell Wildlife Refuge.

In 2008, citing the successful reintroduction of the gray wolf, the USFWS delisted the wolf as an endangered species. Responsibility for wolf population management now passes from the federal government to the individual states of Montana, Idaho, and Wyoming. Each of the states is required to come up with a wolf management plan that will allow for a population of at least 300 wolves, which is the minimum number required to maintain a stable population. In 2008, Montana had at least 422 wolves, including 39 breeding pairs, living in 73 packs. At the time of delisting, the state’s wolf population was increasing about 25 percent annually. As part of its wolf management program, Montana officials are talking about instituting a hunting season for wolves.