Twenty-five years ago this month, 14 wolves from Canada were released into an ocean of elk on the rugged sweep of sagebrush steppe and pine forest of Yellowstone National Park to see what would happen.

The new wolves immediately set to out doing what they do best, hunting prey. What has unfolded since is a remarkable, continuing ecological and social drama that has changed the way biologists think about predators and the animals they stalk. It has also transformed parts of the nation’s oldest national park, redeemed the image of wolves in the popular imagination and inspired similar wildlife experiments around the world.

Wolves were erased from the park and the rest of the Northern Rockies in a sustained campaign of shooting, poisoning and trapping in the early 20th century. They were regarded as vermin, hated by ranchers fearful for their livestock and by hunters and outfitters worried about deer, elk and other quarry. Some of that enmity remains.

But, thanks largely to the wolf’s reintroduction into Yellowstone, their reputation has swung from scourge to savior, at least among some, as biologists have come to understand the wolves’ role in maintaining the park’s ecological balance.