The same is true with many other species - there is a noticeable variation is patagoniensis, aestivus, olfersii and viridissimus. I'd compare it to this: there is also noticeable variation in kingsnake and gopher snakes county to county in California - different patterns, coloration, etc. There is even a secret location in the Bay Area of pacific gophers that look like no other pac gophers anywhere else.
The variety is wide enough in psammophidea that I'd compare it as if we were to group all of the gophers into one species - instead of affinis, deserticola, annectans, etc.
Time will tell............