Using its keen sense of smell, a grizzly bear can detect food from miles away. Despite its looks, this large animal is not an effective hunter, eating mostly plants, insects, and dead animals. As many as 50,000 grizzlies once roamed western North America, across vast stretches of open and unpopulated land from the Pacific Ocean to the Great Plains. As people settled in new towns and cities, these bears were pushed out of their habitat. Control actions to reduce livestock conflict and habitat loss caused the bear to disappear from 98 percent of its former range. The species was listed as threatened in 1975.