I live in New Mexico and here are the 2 most common things I've heard.
My little brother and I had a running joke going when we were kids and it still holds true. If someone see's a snake in the mountains it automatically assumed to be a "timber rattler". If you see a snake in the desert its assumed to be a "diamond back".
We used to go camping and fishing in some local mountains when we were younger and I can't tell you the amount of times we would be warned about timber rattlers. There are no timber rattlers in the NM or the mountains of NM. Once we were driving along and several cars were stopped and a bunch of people were in the road mingling around. As we slowly drove past I noticed they were all looking at a big gopher (bull) snake coiled up on the road. We pulled over and I jumped out and went over to see it. As I was approaching it some guy yelled out to me get back its a "timber rattler". I went over and picked the snake up by the back of the head and walked straight over to the guy and showed him and his whole family that timber rattlers have rattles as I picked up its tail. All of the kids and some of the adults all wanted to touch and pet it.
The other "story" I still hear all the time is about someone lifting up a board in the desert and finding a female rattlesnake gaurding her nest of "eggs". LOL