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, ...

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 ...

A grey wolf prowls through Yellowstone National Park near Mammoth Hot Springs in Montana. A group of 66 wolves was reintroduced to Idaho and Yellowstone in the late 1990s. They now total 2,800 ...

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 ...

Across North America, mountain lions, bears and gray wolves have made a remarkable comeback over the last 50 years. Once nearly exterminated, these animals have been recovering their populations and ...

Across North America, mountain lions, bears, and gray wolves have made a remarkable comeback over the last 50 years. Once nearly exterminated, these animals have been recovering their populations and ...