The story of wolves in Yellowstone National Park is one of the most successful—and scrutinized—wildlife restoration projects ...

Over the last three decades, Yellowstone National Park has undergone an ecological cascade. As elk numbers fell, aspen and willow trees thrived. This, in turn, allowed beaver numbers to increase, ...

A new peer-reviewed study reports that claims of a “world-leading” trophic cascade in Yellowstone National Park are not supported, citing problems with the methods used in earlier research. A newly pu ...

A critique from a team led by Utah State University ecologist Dan MacNulty and published in Forest Ecology and Management has prompted a formal correction to a high-profile study on aspen recovery ...

In Yellowstone National Park — where gray wolves were reintroduced starting in 1995 — researchers have gone back and forth on whether the restoration of wolves has impacted the ecosystem. The idea is ...

Thirty years ago, park rangers reintroduced grey wolves into Yellowstone National Park. They wanted to restore the ecosystem and get the elk... How the wolf changed Yellowstone 30 years after ...

A new analysis challenges one of the most publicized claims about Yellowstone's wolves. In a detailed comment published in Global Ecology and Conservation, researchers from Utah State University and ...

These rare kills in Washington State have biologists searching for answers. “Everyone always assumes wolves have the upper ...

Lang has a close-up view of one of the most dramatic and contentious wildlife experiments in a century—the reintroduction of wolves to the northern Rocky Mountains, where they were wiped out long ago.

This story was updated on January 9, 2026. Since their reintroduction to northwest Colorado in late 2023, wolves have roamed across much of the state. Now, at least one has ventured beyond it: In ...