"In 1930, when wolves disappeared from Yellowstone Park, the ecosystem started to collapse. With no wolves, the elk population exploded, directly contributing to overgrazing of young trees and cottonwood plants. This, in turn, led to a decline in songbirds and beavers, the latter of whom rely on willows in winter. As beavers declined in numbers, the lack of damming and shade meant water temperatures rose, and certain cold-water fish could no longer survive in Yellowstone. The missing link in the ecosystem was clear. So 65 years later, after the last known wolfpack had been exterminated from the area, wolves were reintroduced to Yellowstone in 1995. This hardcover accordion book tells two sides to their story."--Publisher marketing.