Amistad National Recreation Area, an oasis in the desert, consists of the US portion of the International Amistad Reservoir. Its name comes from the Spanish word meaning friendship. It is best known for water-based recreation, camping, hiking, rock art viewing, rich cultural history, and a wide variety of plant and animal life above and below the water. In Southwest Texas, weather can change in a matter of minutes, and the area usually has hot summers and mild winters.