Banded Rock Rattlesnake
In Arizona, the banded rock rattlesnake (Crotalus lepidus klauberi) is restricted to several mountain ranges in the southern portion of the state where it inhabits foothills upwards to pine-fir forests in suitable rocky habitat. It seems to prefer loose rock slides at intermediate elevations, and is often found near permanent or intermittent streams coursing through rocky canyons.
The males are larger and are often colored with a greenish hue.  

In western Mexico, the rock rattlesnake undergoes tremendous variation in pattern and color, closely paralleling the changes in geoformation and lichen growth.  
 
The rock rattlesnakes invaded Arizona millions of years ago from the Sierra Madre Occidental to the south. Subsequent to this period, southern Arizona was subjected to a great deal of faulting and volcanism, followed by weathering and erosion which left this and other Sierra Madrean animal migrants isolated in the mountain ranges where they are found today.
Banded rock rattlesnake - Crotalus lepidus klauberi.  

This species is one of few rattlesnakes which demonstrate sexual dimorphism, in which the mature males are larger and more greenish than the females.