From the beginning, the Nimiipuu lived with nature. From the low Palouse grasslands to the peaks of the Bitterroots, a relationship with the animals of the area was developed.

The wildlife of Nez Perce National Historical Park are as varied as the park's sites. Amphibians, birds, mammals, reptiles, and invertebrates abound at all sites. From the peregrine falcon to the pika, species diversity is of critical importance.

The western portion of the park area is biscected by the Snake and Clearwater rivers and many of their reaches. Many of these drainages have been declared critical habitat for the Snake River sockeye salmon and the Snake River fall chinook salmon, in addition to being important habitat for the West Coast steelhead.

Gray wolf and bald eagle may be periodically seen in the park, but are not residents. Other sensitive species that may also be found in the park include Montana arctic grayling, mountain plover, swift fox, great gray owl, and boreal owl.