Southwestern Speckled Rattlesnake (Crotalus pyrrhus) | Flickr
The Southwestern Speckled Rattlesnake exhibits great variability throughout their range. Their coloration generally matches the tones of the rocks found within their habitat. This, the white variant, lives in an area where the granite is light in coloration with dark flecking.
Or maybe the granite is snakelike? Every think of that, herpetophobe?