DW and I came across a rattlesnake sitting just off the trail while hiking in the Tucson area in March. It was under a small cactus and we didn't see it at all. It warned us though as it started rattling loudly as we got closer to it. When we finally spotted it, it was coiled up and ready to strike, which I'm sure it would have had we gotten any closer. We put the brakes on and slowly backed up and went around him. Took a little while for the DW to find her motivation to continue hiking that day, but she did eventually.