For thousands of years, the people, the Nimiipuu, or Nez Perce have lived in the area minimally covered by Nez Perce National Historical Park.

The Nimiipuu lived across three ecoregions, being: the Shortgrass Prairies of the Palouse Grasslands and Missouri Basin; the Sagebrush Steppe of the Columbia and Snake River Plateaus; and the Mixed Conifer of the Blue Mountains, Salmon River Mountains, basins and ranges of southwestern Montana, and northern Rocky Mountains of Idaho and Montana.

These ecoregions provide a rich and varied environment for the natural resources of the park and surrounding lands. Interaction and use of these resources has been the primary factor for the development of the rich culture of the area.