The mustang is a feral horse breed found in the united states of America. They are also sometimes known as American feral horses, BLM (Bureau of Land Management) horses, or Range horses. The mustang gets its name from the Spanish word mesteño, meaning wild or stray. Being feral, mustangs are very tough and hardy. They have good strong bones and feet, and are usually stocky and well muscled. However, because they are bred in the wild and not for any specific purpose their physical builds vary more than those of domestic horses.