This is Crotalus viridis viridis - the Prairie Rattlesnake. Notice the two pits that look like nostrils. These are the eponymous pits in "pit-viper". My birding friends and I were out in Cottonwood Canyons, CO looking for birds when my friend came within a few steps of standing on this guy. Needless to say it got very aggressive and and curled into the 's' position and was rattling its tail like crazy. The 's' position you can see in this photo, where it doubles back over itself. This position means that if you get closer than about 3 feet, it WILL strike at you. The snake itself was about 3' long. I've never seen a rattlesnake like this before and they're even more impressive than I was expecting.This exact situation is the reason I've been lugging my telephoto everywhere even though I don't feel like shooting birds. Enjoy, and sweet dreams


