In 1995, after an absence of some seventy years, gray wolves were released back into Yellowstone National Park, one of the most ambitious and controversial wildlife restorations ever attempted. The results transformed the ecosystem and reignited a conflict that has raged ever since.

The wolves' return set off a cascade of ecological change that scientists still study. With a top predator back on the landscape, elk behavior shifted, allowing overgrazed streamside vegetation to recover in places, which in turn benefited beavers, birds, and fish. The story became a famous example of how a single species can ripple through an entire ecosystem.

For many, the wolves are a triumph, a restoration of natural balance and a thrilling presence that draws visitors from around the world hoping for a glimpse or a distant howl. For others, chiefly ranchers who lose livestock and hunters who compete for elk, the wolves are an imposition, a predator returned against their wishes.

The animal remains the most divisive in the West, its management a perpetual battleground of lawsuits, hunting seasons, and shifting federal protections. Yet the wolves themselves simply do what wolves do, hunting and raising pups across the Yellowstone region, their return an enduring symbol of both the promise and the friction of restoring the wild.