The northern Rocky Mountain wolf (Canis lupus irremotus ), also known as the northern Rocky Mountain timber wolf, is a subspecies of gray wolf native to the northern Rocky Mountains. It is a light-colored, medium to large-sized subspecies with a narrow, flattened frontal bone. The subspecies was initially listed as Endangered on March 9, 1978, but had the classification removed in the year 2000 due to the effects of the Northern Rocky Mountain Wolf Recovery Plan. On August 6, 2010, the northern Rocky Mountain wolf was ordered to be returned under Endangered Species Act protections by U.S. District Judge Donald Molloy in a decision overturning a previous ruling by the U.S. Fish and Wildlife Service. They were later removed on August 31, 2012 from the list because of Idaho, Montana, and Wyoming meeting the population quotas for the species to be considered stable. This wolf is recognized as a subspecies of Canis lupus in the taxonomic authority Mammal Species of the World (2005).
This subspecies generally weighs 70–150 pounds (32–68 kg) and stands at 26–32 inches, making it one of the largest subspecies of the gray wolf. It is a lighter-colored animal that inhabits the Rocky Mountains with a coat including far more white and less black. In general, the subspecies favors lighter colors, with black mixing in among them. Its population currently resides in western Montana, eastern Idaho, western Wyoming and southern Alberta.
The northern Rocky Mountain wolf preys primarily on the bison, elk, the Rocky Mountain mule deer, and the beaver, though it is an opportunistic animal and will prey upon other species if the chance arises. But, for the most part, small prey animals do not make up a large part of its diet.
When an individual or a pack is able to take down numerous prey, the amount a northern Rocky Mountain wolf eats daily will generally make up about 10–21% of its body mass, though there have been recorded instances of an individual eating up to 37% of its body mass. However, when prey is not as plentiful, northern Rocky Mountain wolves are able to survive for considerably long periods of time while eating only small amounts. Cannibalism, in times of severe food shortage, occurs, as a pack will kill and eat an injured or weak member of the group.
The Northern Rocky Mountain Wolf Recovery Plan was first approved in 1980, though it was then revised later on in 1987. The plan required a certain population of northern Rocky Mountain wolves to reside in the area inside and around Yellowstone, which included at least ten breeding pairs, and for the population to remain stable for at least three consecutive years. However, the northern Rocky Mountain wolf was not, at the time of the initial drafting, recognized as a legitimate subspecies, so the wolves involved in the plan were instead the Mackenzie Valley wolf. The overall reason for this was that the stated two subspecies of wolf roamed in the same general area as the northern Rocky Mountain wolf and because the plan covered the reintroduction of wolves into the area in general. For this reason, the more plentiful subspecies were chosen to be trans-located, so as to not upset the balance in the areas they would be taken from. In 1995, wolves were reintroduced to Yellowstone National Park and the Frank Church–River of No Return Wilderness.
In response to concerns about wolves being allowed to run free in the area, killing livestock without any allowed repercussions, the final draft of the plan, completed on November 22, 1994, outlined that ranchers were allowed to kill wolves if they were "caught in the act of killing livestock on private property".
In three lawsuits combined as Wyoming Farm Bureau Federation v. Babbitt, opponents of reintroduction argued that the reintroduced wolves threatened wolves that might already inhabit the area, while supporters argued against the experimental designation and for fully protected status. District Court Judge William F. Downes ruled that the re-introduction violated section 10(j) of the Endangered Species Act; however, this ruling was overturned by the Tenth Circuit Court of Appeals.
