What Spaniard fought the Tiwa Indians and saw the Colorado River?
Tiguex War:  It was fought in the winter of 1540-41 by the expedition of Francisco Vázquez de Coronado against the twelve or thirteen pueblos of Tiwa Indians as well as other Puebloan tribes along both sides of the Rio Grande, north and south of present-day Bernalillo, New Mexico, in what was called the Tiguex Province. Francisco Vázquez de Coronado: Francisco Vázquez de Coronado y Luján (1510 – 22 September 1554) was a Spanish conquistador and explorer who led a large expedition from Mexico to present-day Kansas through parts of the southwestern United States between 1540 and 1542. Francisco Vázquez de Coronado:  His expedition marked the first European sightings of the Grand Canyon and the Colorado River, among other landmarks.
Francisco Vázquez de Coronado