Drawing on extensive ethnographic work among descendant native peoples and ongoing archaeological excavations, Mountain Spirit shows that many groups have visited or lived in the area in prehistoric and historic times. Primary among them was the Shoshone group called Tukudika, or Sheep Eaters, who maintained a rich and abundant way of life closely related to their primary source of protein, the mountain sheep of the high-altitude Yellowstone area.

Prepared following the 2007 GSA Annual Meeting in Denver, Colorado, these 15 guides illustrate the latest geological and archeological thinking on a variety of current research themes.