This natural pool in Big Bend National Park was named Ernst Tinaja, after Max Ernst, one of the early settlers of the area. Tinaja is a Spanish word meaning "large earthen jar" which refers to the basin-shaped water hole carved into bedrock by way of erosion. Tinajas are one of the few sources of water found in the midst of the Chihuahuan Desert inside the park. Insects, birds, lizards, and small mammals depend on these oases for survival. This one is situated on the dry wash of a narrow canyon, the walls of which provide welcome relief from the rays of the blazing sun. When the water level becomes low as it is in this photo, animals sometimes drown because they fall in and are unable to climb back out. The park ranger told me the story of one hiker who had been swimming in there and died because the water had been very low and the walls were too high and too slick to climb out of. Eventually, his muscles were so exhausted from treading water that he drowned.