I lucked out and got a couple of pictures of my Organ Pipe rattlesnake.
First, here's the mine entrance about half a mile off. see the pile of earth and rock just to the left of the big cactus? Those waste piles are always a dead give-away if you're looking for mine openings.
Final score: Snake: 1, Murphy's Law: 0.
Still, he was a beauty, wasn't he?