Juan de Onate's main contribution and the one that he is most known for is being the official founder of New Mexico. Although there were already natives settled there, he colonized the area, and was its first governor.
Juan de Onate is also famous for founding the El Camino Real. The path that he made was used as means of passing back and forth for a long time. We have modernized this course with I-25, the interstate that lines the path and serves as the most significant means of passing through New Mexico. This path was considered the interstate of its time. It is sometimes referred to as "the royal road" because it passes through all of the significant cities in New Mexico, including Santa Fe.