QS, that's just about the scariest rattler shot I've ever seen. Black and white ringed tail, so I'm assuming it's a western diamondback?
It could also be a Red Diamond Rattler... they have the same black/white banding on their tails and tend to have more of the reddish coloring then the Western Diamondback...
As for snakes above 6K or so.. the Sierra Garter snake to about 8k, the Southern Pacific Rattlesnake to about 11k, The Panamint Rattlesnake to about 8k... just to throw a couple names out there....
