"Badlands National Park" - South Dakota - 8.22.2006

Containing the world’s richest Oligocene epoch fossil beds, dating 37-28 million years old, the evolutionary stories of mammals such as the horse and rhinoceros arise from the 244,000 acres, 381 square miles of sharply eroded buttes, pinnacles, and spires. Bison, bighorn sheep, endangered black-footed ferrets, and swift fox roam one of the largest, protected mixed-grass prairies in the United States.