Some 10 million years ago, up to a dozen species of horses roamed the Great Plains of North America. They were initially smaller than todays horses and had three toes; some lived in primeval forests. Others became larger with single hooves and ate grass on the plains. The horse then became extinct in North America about 12,000 years ago. However, the Spanish explorers brought domesticated horses from Europe in the late 15th century. The first horses to return to the continent were 16 horses brought by the explorer Hernan Cortes. Some inevitably escaped and developed into wild herds. Wild mustangs roaming the west were descendants from these Iberian horses. Nearly ten years ago, Flint Hills ranchers convinced the Bureau of Land Management to reintroduce wild horses into Kansas where they could run on the prairie. There are now 7,000 roaming some 60,000 privately owned acres in the Flint Hills of Kansas.
For more information on horses from the American Museum of Natural History, visit: http://www.amnh.org/exhibitions/past-exhibitions/horse/the-evolution-of-horses