The Great Plains stretched from the eastern edge of the Rocky Mountains out to the Mississippi River. This vast region of rolling hills and regular rainfall was covered in wild grasses. These grasses supported a wide variety of wildlife, which included bison herds that were almost unimaginable in size.
These herds could stretch across miles of terrain and include millions of individual animals. The peoples who lived in this region depended heavily on the bison as a source of food as well as skins which they used to create clothing and shelters.