According the Bureau of Land Management, feral horses can be found in Arizona, Nevada, Wyoming, Montana and North Carolina. Modern horses are descended from species that originated in Eastern Europe, Asia and Mongolia, and wild specimens still live in these regions.
Wild horses in America went extinct approximately 10,000 years ago along with many other large, browsing mammals. It wasn't until the 16th century that the horse was reintroduced to the continent by the Spanish. Those same horses later formed the foundation of the feral mustang herds that survive today. As of May 2014, approximately 38,000 wild or feral horses roam the open spaces of America and are recognized by Congress as a symbol of the West.