Ambling gaits are often genetic in some breeds, known collectively as gaited horses. Often, gaited horses replace the trot with one of the ambling gaits. The Spotted Saddle Horse developed from small gaited pinto ponies of Spanish ancestry. Some Curlies have been crossbred to gaited horses. Some horses without apparent inborn gaited ability can be taught to "gait" or amble. The "Nez Perce Horses" are often gaited, with a fast and smooth running walk. They are a gaited breed, with an ambling gait. In most "gaited" breeds, an ambling gait is a hereditary trait. Others, such as certain bands in Wyoming, have characteristics consistent with gaited horse breeds. However, pacing in gaited horses is often, though not always, discouraged. In the United States horses that are able to amble are referred to as "gaited". Horses that amble are sometimes referred to as "gaited", particularly in the United States. Crosses with gaited breeds are not accepted for registration. It is used most often on the high-action and gaited horses of the Americas. Some individuals are gaited, with a range of different footfalls accepted.