The only cause which I can imagine for this choice, is its being a landmark in a dangerous passage.

The Sierra de la Ventana is visible at an immense distance; and a Gaucho told me that he was once riding with an Indian a few miles to the north of the Rio Colorado, when the Indian commenced making the same loud noise, which is usual at the first sight of the distant tree, putting his hand to his head, and then pointing in the direction of the Sierra.
Upon being asked the reason of this, the Indian said in broken Spanish, "First see the Sierra." About two leagues beyond this curious tree we halted for the night: at this instant an unfortunate cow was spied by the lynx-eyed Gauchos, who set off in full chase, and in a few minutes dragged her in with their lazos, and slaughtered her.

We here had the four necessaries of life "en el campo,"-- pasture for the horses, water (only a muddy puddle), meat and firewood.

The Gauchos were in high spirits at finding all these luxuries; and we soon set to work at the poor cow.

This was the first night which I passed under the open sky, with the gear of the recado for my bed.