Which Plateau tribes became known for breeding large herds of horses?

Following the arrival of the horse in the 18th century, several Plateau tribes became renowned for their significant horse herds and advanced equine breeding programs.

European and Euro-American traders noted that the following tribes possessed larger herds than many of their counterparts on the northern Plains from the early 19th century onward:

• Nez Percé
• Cayuse
• Walla Walla
• Flathead

The Nez Percé were particularly notable for their sophisticated approach to animal husbandry; they were almost unique among Native American groups for conducting a selective breeding program, which was instrumental in the creation of the Appaloosa breed.123