Throughout the colonial period, the Spanish attempted to Hispanicize the Indians along the northern frontier of New Spain. The conquistador, the missionary, the civilian settler, and the presidial soldier all took part in this effort. At La Junta de los Rios, a fertile area inhabited by both sedentary and semi-sedentary Indians, each of these institutions played a part in fundamentally changing the region and its occupants. This research, relying primarily on published Spanish source documents, sets the effort to Hispanicize La Junta in the broader sphere of Spain's frontier policy.