Navajo-Churro ram. These sheep, descended from the Churra, an ancient Iberian breed, were brought to the southwest with Juan de Oñate y Salazar (1550–1626). They are well suited to extremes of climate. Some rams have four fully developed horns, a trait shared by few other breeds of the world. That these sheep still exist today is a testimony to their endurance. No other sheep population in the history of the world has survived such selective pressure with such dignity and spirit.