Please answer the following question: Rio Salado (New Mexico) - The Rio Salado is a tributary of the Rio Grande in the U.S. state of New Mexico. From its source in northeast Catron County it flows about 86 miles (138 km) generally east to join the Rio Grande just north of Polvadera and about 15 miles (24 km) north of Socorro. The name Rio Salado is Spanish for salty river. Given a choice of categories company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, the text refers to which one?
A:
Natural Place