Starting in the 1940s, park managers, biologists, conservationists and environmentalists began what would ultimately turn into a campaign to reintroduce the gray wolf into Yellowstone National Park. When the Endangered Species Act of 1973 was passed, the road to legal reintroduction was clear (Urbigkit, 2008). In 1995, gray wolves were first reintroduced into Yellowstone in the Lamar Valley (Duffield, Neher & Patterson, 2006). The history of wolves in Yellowstone chronicles the extirpation, absence and reintroduction of gray wolves to Yellowstone, and how the reintroduction was not without ...