This book presents the history and aftereffects of the fires of 1988 that swept through the Greater Yellowstone ecosystem (GYE) describes the chronology of the fires, the areas burned, and the extent of fire in those regions. One of the biggest concerns of the public was how individual plants and animals fared. Thinking hierarchically, we know that the patterns seen at the community and ecosystem levels are the result of mechanistic responses at the individual and population levels. It is important to know how forest trees and grass-land species responded. Some of the greatest public concern was for large animals, particularly Elk. Elk mortality and population responses after the fires took some surprising turns. The GYE is an extremely heterogeneous environment. Plant communities provide essential habitat for the megaherbivores of the GYE as well. Although we know numbers and how the populations of these animals have changed since the fires, it is difficult to determine the mechanisms behind these changes. Using simulation models and comparing their results with reality can yield important insights as to the mechanisms governing ungulate response to fire. The sediments of Yellowstone's lakes provide an opportunity to reconstruct the vegetation and fire history of the region back to the time of late-Pleistocene deglaciation.