Seattle Times: The reintroduction of wolves to Yellowstone was one of the greatest achievements in the history of wildlife conservation in North America, said Tom Hobbs, professor emeritus at Colorado State University and the lead author of a long-term study on the role of apex predators in restoring ecosystems. In the 1990s, about seven decades after the last wolf pack was killed in Yellowstone National Park, officials relocated 41 gray wolves to the park.

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