This 50-million year old lake bed is one of the richest fossil localities in the world. Recorded in limestone are dynamic and complete paleoecosystems that spanned two million years. Preservation is so complete that it allows for detailed study of climate change and its effects on biological communities.

Visitors discover that this resource displays the interrelationships of plants, insects, fishes, reptiles and mammals, like few other known fossil sites. The relevance and challenge of study and preservation of this ancient ecosystem are equal to those of a modern ecosystem.

The surface topography of Fossil Butte is now covered by a high cold desert. Sagebrush is the dominant vegetation at the lower elevations, while limber pine and aspen occur on the slopes. Pronghorn, Mule deer and a variety of birds are commonly seen. Moose, elk and beaver are sometimes observed.