Two Horned Serpents From Gallisteo Basin, New Mexico
Our modern culture tends to regard the serpent as a representation of evil, having lost the memory of the dual nature of this symbol. However, dust off your Bible, and look in Exodus 7:9-12 for the story of Moses in the Pharaoh's Court. Moses ordered his staff to be thrown down, and it changed into the serpent representing the forces of Good, and successfully battled the serpents of the pharaoh's sorcerers that represented Evil.
The image of the dual serpents, twining about a staff, that makes up makes up the respected medical symbol of the caduceus, dates back to Babylon. Somehow our culture has forgotten this "good" aspect of the serpent.
Southwestern iconography regarding the serpent all goes back to the legend of Kukulcan/Quetzalcoatal, represented as a feathered serpent. Quetzalcoatl was associated most intriguingly with legends of a white bearded hero arriving by boat from the sea, teaching the people, and then leaving, with the promise to return again in the future. This long-lived legend is one of the factors that permitted the quick and easy overthrow of the Aztec Empire by Spanish invaders. By the time the Aztec realized that Cortez was certainly no Quetzalcoatl returning, it was too late!