Of the four types of Border Collies, the Nap Type is the only smooth coated one. The name comes from a dog called Whitehope Nap. These dogs are strong, fast and powerful. Their coat is short, but has an undercoat to act as insulation from cold or heat. Many have longer legs and shorter bodies, making their outline more square than the other types. Because of their short coats, speed, and power, many Americans used them to work cattle on large ranches in the Southwest.