The night snakes in this portion of Cochise county have been shown by DNA analysis to be a distinct clade that is being treated as a separate, not-yet-described species. They are sometimes referred to as "Hooded Nightsnakes" since at least most of them have a thick dark neckband with a size and shape as seen here. However, nightsnakes are quite variable in pattern, and this type of "hood" is sometimes seen on individuals from other areas, so it's not a completely solid diagnostic character.