Brief Park History - Rocky Mountain National Park (U.S. National Park Service) While massive glaciers shaped the meadows and peaks, Rocky was an inhospitable land. It was not until some 11,000 years ago that humans began venturing into these valleys and mountains. Spearheads broken in the fury of a mammoth's charge and scrapers discarded along a nomad's trail tell us little about the area's early native peoples. Even though it was never their year-round home, the Ute tribe favored the areas green valleys, tundra meadows, and crystal lakes. The Utes dominated the area until the late 1700s.