Yellowstone Wolf Project

Yellowstone Wolf Project

One of Yellowstone’s most important predators, who roamed its landscape and defined its ecosystem for thousands of years, completely disappeared in the early part of the 20th Century. By the 1920s, the last wolf pack in Yellowstone was killed, in an effort by the U.S. government to tame the wilderness. This action had a profound effect on Yellowstone. Elk and coyote populations boomed. Beavers became increasingly rare, and so did willow and aspen trees. The park was missing a keystone species and it affected the balance of the entire ecosystem.

But the tide began to turn with the help of the watershed Endangered Species Act, one of a few dozen United States environmental laws passed in the 1970s. With its passing, the stage was set for the return of the wolf to Yellowstone when the gray wolf was listed as endangered and recovery mandated in 1974. Immediately, the National Park Service began planning a wolf homecoming in Yellowstone—their native territory and historic home.

It took 21 years, but in January 1995, all the pieces were in place. Fourteen gray wolves were captured in Canada and relocated to Yellowstone’s Lamar Valley. In 1996, 17 more Canadian wolves were brought into the park, followed by 10 wolves from northwestern Montana in 1997. The wolf population grew quickly, as pack territories and breeding pairs were established.

This monumental undertaking marked the first deliberate attempt to return a top-level carnivore to a large ecosystem. Its impact has been significant; wolves have affected the dynamics of the entire Yellowstone ecosystem.

Yellowstone Forever Support

While the federal government funded the original restoration and monitoring of wolves from 1995-1996, this funding dried up. The fledgling Yellowstone Park Foundation (now Yellowstone Forever), established in 1996, stepped in to raise private contributions to continue wolf research and monitoring in the park. “If it wasn’t for the Yellowstone Park Foundation, the whole thing could have gone down the tubes in those early years,” said Smith. “Thanks to the donors, Yellowstone has the most recognizable wolf conservation program in the world and is conducting cutting-edge research.”

Wolf research and monitoring in Yellowstone is a year-round strategy that is critical to the long-term health of wolves in Yellowstone. Yellowstone’s wolf biologists and field staff conduct research efforts to capture and collar wolves, gather genetic samples for testing and lab work, conduct winter/summer field studies on predation and pup survival, and log numerous aerial monitoring flights. This level of fieldwork and science helps the park better understand the wolf population and territories, their relationships with prey species (like elk and bison), monitor the health of packs, and identify disease or health issues in the population.

Support the Yellowstone Wolf Project



Wolf Project Annual Reports 

Q&A Video with Doug Smith, Yellowstone Wolf Project Leader

Wolf Project Information from the National Park Service


All images courtesy of the National Park Service