the reintroduction included hunters concerned that wolves would inhibit their ability to hunt the highest number of game species possible, ranchers concerned for the welfare of their animals, and land developers concerned that a species listed under the Endangered Species Act may restrict what they can do to their land. Along with cougars, timber wolves are the largest top predators that live in the forest and have no predators of their own except humans. Most of the area's native mammal species are present in the forest, with the exception of grizzly bears, which have become locally extinct. Plans for their reintroduction to central Idaho have been proposed since the 1990s, but have not progressed because of concerns similar to those with the wolf reintroduction as well as fears for human safety. The northern and high elevation areas of the forest contain habitat for wolverines and the endangered Canadian lynx, but no recent sightings of these species have been reported. Elk (also known as wapiti), mule deer, and pronghorn (also called pronghorn antelope) are some of the most commonly seen large mammals. During winter, pronghorn that spend the summer in the Sawtooth Valley migrate south to the lower elevations on the Snake River Plain, and some sections of the forest are closed to motorized use to protect the elk winter range. Bighorn sheep are rare sights in the forest, but the forest contains one-third of Idaho's mountain goat population, and they are commonly seen at high elevations in the Boulder, White Cloud, Pioneer, and Sawtooth mountains. Other mammals in the forest include the coyote, moose, bobcat, beaver, yellow-bellied marmot, pika, and badger. Bull trout are one of the management indicator species for the forest. Population monitoring efforts are undertaken every year to provide an assessment of forest health. They were selected because they are dependent upon specific habitat conditions and are sensitive to habitat changes. Bull trout are only found in parts of the Salmon, Boise, and Payette river watersheds on the Fairfield District and the SNRA. The forest is home to the longest salmon migration in the continental United States, but with the damming of the Columbia River, salmon populations have collapsed. Redfish Lake was named for the sockeye salmon that would return to breed in the lake and its tributaries and historically had 10,000 to 35,000 adult fish return to the lake annually. Between 1990 and 1998 a total