In addition to these faults, Yucca Mountain is criss-crossed by fractures, many of which formed when the volcanic units cooled.

A series of large explosive volcanic eruptions occurred to the north of Yucca Mountain millions of years ago, producing dense clouds of volcanic ash and rock fragments which melted or compressed together to create layers of rock called tuff, forming the mountains and hills of the region.

The volcanic eruptions that produced Yucca Mountain ended about 12 million years ago.

The remaining volcanic material (less than one percent) in the Yucca Mountain region is a result of these smaller eruptions.

Yucca Mountain and surrounding lands were central in the lives of the Western Shoshone and Southern Paiute peoples, who shared them for religious ceremonies, resource uses, and social events; Yucca Mountain continues to be considered sacred by the Shoshone people living today.