Cool pic. Yeah I find them above 6,000. Found them at 7-8,000. And not very often, but a few here at 9,200. It's hard on them, but a few can survive, generally garter snakes, at higher elevations. Winters are getting milder so they can do better. One thing I have noticed is you don't see venomous snakes much above 6,000ft. Our winters get shorter, temps get a little warmer, probably the rattlesnakes will expand their range.
Those bullsnakes are great at keeping Vols from tunneling under your lawn. I leave them alone when I see em snaking around the foundation of the house and in and around the shrubs.