In the 1990s, the federal government reintroduced the gray wolf to Yellowstone National Park. It was considered a big success. And that’s when the real fight began.

Some call it one of the great conservation success stories of our time. After being nearly killed off, gray wolves were re-introduced to Yellowstone National Park in 1995.

Since then, the population has bounced back to more than 1,600 across the northern Rocky Mountains. But some say a protracted fight over whether the wolves remain endangered has had some unintended consequences.