Wolves were trapped, shot from planes and snowmobiles, and hunted with dogs. Animal carcasses salted with strychnine were left out for wolves to eat. This practice killed millions of wolves and, indiscriminately, also eagles ravens, foxes, bears, and other animals, which also fed on the poisoned carrion. These practices are still used today in areas where wolves are not legally protected. Numbers are unknown in Washington, North Dakota, and South Dakota.
Populations fluctuate due to food availability and strife within packs.
The gray wolf is listed under the Endangered Species Act as a threatened species in Minnesota, and as an endangered species elsewhere in the lower 48 states. In Alaska, wolf populations number 5,900 to 7,200 and are not considered endangered or threatened. The Canadian wolf population is estimated 50,000. Wolves seldom kill livestock. Many more cows and sheep die of disease, weather, attacks from dogs, or abandonment.