Western Diamond Back Rattlers (from Idaho) are very dangerous. I couldn't find a picture close to remembling the type I have seen, but I did find this picture: Diamond Backs, no matter how big they get, are capable of walking on their tails, climbing trees or jumping up from rocks (out of nowhere)! They are deadly snakes. If per chance you are bit by one and no help is around, you only have a small window time to get help. Maybe half an hour to an hour? Depending on how severe the bite is or items about the snake bite victim. It's always wise, in Idaho, to carry a snake bite kit and a gun if you're out on the desert or up in the mountains or down by a river. Baby Diamondback rattlers are quick, fast to jump from their nest. I nearly got bit one time, it scared me to death!
I've seen Diamondbacks coiled up on a deserted backroad in Idaho... he was probably about nine to 10 foot long, probably a circumference of about the size of a muscular bicep of a pro-westler, baking on an old cement highway in broad daylight. It's always wise to keep your distance from Diamondbacks.