As many as 50,000 grizzlies once roamed the Western U.S. They’ve always played an important role in the ecosystem. For example, they keep the numbers of other animals, like elk, from getting out of control.
But in the 1800s, settlers began building houses and farms on the land where the grizzlies lived. This destroyed much of the bears’ habitat. Ranchers also shot the bears to protect cattle, and hunters killed the bears for sport.
The grizzly population dwindled. By the 1970s, there were fewer than 140 grizzlies in the Yellowstone area.