It was near Soda Butte in 1924 that the last Yellowstone gray wolves — two pups — were killed by rangers. Wolves remained starkly absent from the landscape until 1995, when the first experimental packs of gray wolves (Canis lupus) were brought from western Canada to the Lamar Valley to repopulate Yellowstone and restore a natural balance to the Park’s wildlife.

Proposed legislation would remove wolves from endangered species protection »»

Today, there are three different, recognized wolf species in North America: the gray wolf (Canis lupus), the red wolf (Canis rufus) and the coyote or "brush wolf" (Canis latrans). The origin of the red wolf has been debated extensively, as some biologists believe that it is simply a gray wolf/ coyote hybrid. Others believe that it is a true species.

Eastern Gray Wolves – Are they really Red Wolves? »»