From USDA/APHIS publication:
Non-Lethal and Lethal Tools to Manage Wolf-Livestock Conflict in the Northwestern United States
Gray wolf populations were eliminated from the northern Rocky Mountains of the western United States by 1930, largely because of conflicts with livestock. The wolf population is now biologically recovered and over 1,020 wolves are being managed in Montana, Idaho, and Wyoming under the federal Endangered Species Act. From 1987 to December 2005, 528 cattle, 1,318 sheep, 83 dogs, 12 goats, 9 llamas, and 6 horses were confirmed killed by wolves, and over $550,000 was paid from a private damage compensation fund. To help restore the wolf population, we used 22 variations of non-lethal control tools, relocated wolves 117 times, and killed 396 wolves to reduce conflict between wolves and livestock. A variety of tools, including regulations that empower the local public to protect their private property, reduced the probability of wolf-caused damage. This wolf population was restored, the risk of livestock damage reduced, and public tolerance of wolves improved through an integrated program of proactive and reactive non-lethal and lethal control tools. Reduced conflict increases the potential to restore wolf populations.
The gray wolf (Canis lupus) is the most widely distributed large carnivore in the northern hemisphere (Nowak 1995). In the western United States, elimination of wild prey by colonizing settlers, wolf depredation on livestock, and negative public attitudes towards wolves resulted in the extirpation of wolf populations by 1930 (Mech 1970, McIntrye 1995). In 1974, gray wolves were protected and managed by the U.S. Fish and Wildlife Service (USFWS) under the federal Endangered Species Act of 1973 (ESA). Wolf recovery would have been impossible if abundant wild ungulate prey had not already been restored by sportsmen and the state wildlife agencies (Bangs et al. 2004). As a result of abundant wild prey and increased protection of wolves in Canada, the first recorded den in the western U.S. in over 50 years was established in Glacier National Park in 1986 by wolves that naturally dispersed from Canada (Ream et al. 1989). Wolves from Canada were reintroduced to central Idaho and Yellowstone National Park in 1995 and 1996 to accelerate restoration (USFWS 1994a, Bangs and Fritts 1996, Fritts et al. 1997). Restoration of wolves emphasized legal protection, minimizing conflicts with livestock, and building local public tolerance (USFWS 1987, 1988). Read more.