Millions of years have passed in the history of South Dakota and, as time has passed, the plants, animals, climate, and topography have changed. Fossil records along with geological records hold information that help paleontologists explain these changes. The geological record tells us how the surface of the earth was transformed, which helps explain the changes in the climate. These changes, in turn, affect the composition and distribution of the flora and fauna found in North America.
Rock layers which preserve the fossil record can also provide clues to the prehistoric sequence of events. As we study the past, we find explanations for the current plant and animal composition of the Black Hills and the surrounding plains.
For more information about the geological time line of the park click here.
Last updated: February 26, 2019