To the Ysleta del Sur Pueblo Indians, the water of the Rio Grande that divides the United States and Mexico sanctifies religious rites and purifies their hunts.

Indian communities living miles away use the river to send messages to fellow tribes downstream, said tribal chief Jose Sierra.

"They go to the river and talk to the river, and the river sends it down," said Sierra, a barrel-chested man with long, graying hair and thick turquoise bracelets at his wrists.