People are what make archeological and historic places interesting. Who were they? How did they live? What did they leave behind? Through examination of material remains, like remnants of ancient walls, artifacts, traces of roads, and even symbols on rock, researchers pull together stories of the past. Petrified Forest National Park has a remarkably diverse and long human history. Evidence shows there are over 13,000 years of human occupation. People first came to the area in nomadic groups following the last Ice Age, and have been present ever since.