Yellowstone is working to piece together some of its lost history. Long before it was a park, native people hunted and camped on the land for at least 11,000 years. When it became a national park, the U.S. government pushed the natives out. In the last 30 years, the National Park Service has made efforts to research the park’s history. A team of researchers has been excavating the park for 14 years. They found weapons made of volcanic rock, artifacts, and evidence of bison kills. The team hopes their findings will lead to more signs and exhibits in the park about the original inhabitants.