ranchers. Local industry and environmental groups battled for decades over the Yellowstone and Idaho wolf reintroduction effort. The idea of wolf reintroduction was first brought to Congress in 1966 by biologists who were concerned with the critically high elk populations in Yellowstone and the ecological damages to the land from excessively large herds. Officially, 1926 was when the last wolves were killed within Yellowstone’s boundaries. When the wolves were eradicated and hunting eliminated, the elk population boomed. Over the succeeding decades, elk populations grew so large that they unbalanced the local ecosystem. The number of elk and other large prey animals increased to the point that they gathered in large herds along valley bottoms and meadows, overgrazing new-growth vegetation. Because of overgrazing, deciduous woody plant species, such as upland aspen and riparian cottonwood, became seriously diminished. So, because the keystone predators, the wolves, had been removed from the Yellowstone-Idaho ecosystem, the ecosystem changed. This change affected other species as well. Coyotes filled in the niche left by wolves, but could not control the large ungulate populations. Booming coyote numbers, furthermore, also had a negative effect on other species, particularly the red fox, pronghorn, and domestic sheep. Ranchers, though, remained steadfastly opposed to reintroducing a species of animal that they considered to be analogous to a plague, citing the hardships that would ensue with the potential loss of stock caused by wolves. The government, which was charged with creating, implementing, and enforcing a compromise, struggled for over two decades to find middle ground. A wolf recovery team was appointed in 1974, and the first official recovery plan was released for public comment in 1982. General public apprehension regarding wolf recovery forced the U.S. Fish and Wildlife Service to revise their plan to implement more control for local and state governments, so a second recovery plan was released for public comment in 1985. That same year, a poll conducted at Yellowstone National Park showed that 74% of visitors thought wolves would improve the park, while 60% favored reintroducing them. The preparation of an environmental impact statement (EIS), the last critical step before reintroduction could be approved, was halted when Congress insisted that further research be done before an EIS was to be funded. In 1987, in an effort to shift the burden of financial responsibility from ranchers to the proponents of wolf reintroduction, Defenders of Wildlife set up a "wolf compensation fund"