Photographer Tom Murphy has documented the park's wildlife for decades. Now, one of his photos will be on a Forever Stamp.

(ABC) — An upcoming U.S. postage stamp will pay homage to the bison — the United States’ national mammal and one of the most iconic wildlife species at Yellowstone National Park. The new stamp ...

It’s a reminder of the enduring legacy of America’s largest and national mammal — and that their continued presence on the planet is far from assured.

An upcoming U.S. postage stamp will pay homage to the bison -- the United States' national mammal and one of the most iconic wildlife species at Yellowstone National Park. The new stamp features an ...

It’s an animal-eat-animal world out there, especially in Yellowstone National Park. There are almost 70 different mammal species in Yellowstone, and most of those can be separated into two categories: ...

Across Montana’s eastern plains, few sights register as strongly as a bison herd navigating open grassland. Although the grizzly bear is the official state animal, the plains bison has come to ...

Yellowstone National Park’s grizzly bears are beginning to emerge from hibernation, and biologists have already documented the first sighting of the spring seas ...