This guy (Western Diamond Back) was laying in the trail and didn't give us a warning buzz until I stepped within 1 foot of his head. We were both so intent on watching where we stepped on this rocky path that we failed to see this guy until he warned us. I froze in place but Jackie grabbed my arm and dragged me backwards to a safe distance. He wouldn't leave so we walked back up the trail about 50 ft to give him space. He then slowly slithered under the protection of a trail side prickly pear and let us pass.