In the rugged Rocky Mountain foothills of southern Alberta and the remote interior of central B.C., a once hardy and abundant band of wild horses now faces an uncertain future. Their ancient ancestors once roamed the Canadian plains, sharing the terrain with the giant woolly mammoth. But the North American horse was eventually driven to extinction. Eleven thousand years later, Spanish conquistadors returned the horses to the West, where they re-settled into their original range. By the end of the 19th century, 50,000 grazed Alberta and B.C.'s grasslands, but now, only a few hundred wander the forested foothills. With their territory being scarred by clear-cuts and crisscrossed by pipelines, and their very existence being challenged by some who see them as rogue trespassers, many are worried the wild mustangs may once again become extinct.