I still chuckle at my Cresco tank experience in 2011, on the hike down the road I noted a snake skin but didn't think anything of it (pretty common sight here in Australia), I was more concerned about bears, I had a bit of a morbid/curiosity/paranoia about meeting one while hiking after trains.
At the tank we met a Californian, we photo'd the train and walked back up to the cars, he couldn't have noticed the snake skin on the way down, when he saw it with us he was jumping around trying not to be on the ground and as us Aussies would say, he was literally sh##ing himself about a snake being somewhere!
And all I was concerned about was a bear coming out of the woods!
Never did see one.
Wayne from Oz