Pedro de Rábago y Terán
As an explorer in the late 1740s he went on three expeditions to the confluence of the Rio Grande and the Rio Conchos , known as La Junta de los Rios , in order to establish a presidio or military camp to serve six missions in the area of La Junta , which were being attacked by the Apache . 
<triplet> Rio Grande <subj> Rio Conchos <obj> tributary <triplet> Rio Conchos <subj> Rio Grande <obj> mouth of the watercourse