The Hagerman horse is an extinct species of horse that lived during the late Pleistocene epoch, around 1.8 million to 10,000 years ago. Fossils of this horse have been primarily found in North America, particularly in the Hagerman Fossil Beds National Monument in Idaho. It is believed to be one of the earliest ancestors of modern horses. This horse was similar in size to today's Arabian horse, standing about 14 to 15 hands tall. The Hagerman horse had a stocky build and was adapted to a variety of environments, which contributed to its widespread distribution across North America during its time.