As the ice age waned, the milder climate and the mixed vegetation meant the plains were able to support a range of wild life as diverse as Africa Serengeti today. There were at least five kinds of horse, including a wild ass, and another that resembled modern zebra, and North America's very own antelope—the pronghorn.  13,000 years ago, several different species roamed the plains. 

 

The pronghorn lived alongside other grazers still around today, including bison. This animal was common, too.  But now it would seem very out of place. 

 

Bigger than its modern relatives, the ice age camel was extremely hardy, able to eat almost any kind of food. 

 

Elk, like many ice age animals, survive almost unchanged. The rich parkland was ideal for these large deer. But one creature more than any other has remained a constant symbol of the plain since people first set foot here, the bison. 

 

Adult bison are formidable, two meters tall and weighing more than a ton. They too sheltered near the trees in winter, taking to the plains again in spring when new grass started sprouting.