What explorer first visited the U.S. river, which is the largest within its state, creating a natural boundary with Mexico?
Captain General Juan de Onate
Juan de Oñate y Salazar (1550–1626) was a conquistador from New Spain, explorer, and colonial governor of the Santa Fe de Nuevo México province in the Viceroyalty of New Spain. He led early Spanish expeditions to the Great Plains and Lower Colorado River Valley, encountering numerous indigenous tribes in their homelands there. Oñate founded settlements in the province, now part of the present-day American Southwest.
Rio Grande, Spanish Río Grande del Norte or (in Mexico) Río Bravo or Río Bravo del Norte , fifth longest river of North America, and the 20th longest in the world, forming the border between the U.S. state of Texas and Mexico.