Diamondbacks are usually the most commonly found rattlesnake within the range of this work. The largest one I have found in the Trans-pecos region was a 6'4" specimen found a couple of miles south of Juno, Val Verde county, but the average will be 3'-4'. Most of the specimens seen will probably be under two feet in length.
There is a bit of color variation along the range, but not much. Many of the diamondbacks I have found around Fort Stockton have been a grayish color. If you are not used to seeing the rattlesnakes of west Texas, diamondbacks can be confused with prairie and Mojave rattlesnakes.
This C. atrox was photographed at night on a rock cut in northeastern Val Verde county, on Hwy. 277
This picture is of a diamondback from far southern Presidio County, south of Lobo It is much redder than other atrox I have seen. Thanks to Jeff Ross for letting me photograph the animal.