As venomous snakes go, rattlers tend to be a bit more camo'd than, say, brilliantly colored eyelash vipers. I'm glad you didn't get hurt, I've been in very similar situations more times than I can count, and once is too many for me!

I have stepped literally on top of cottonmouths, tripped on copperheads, and stepped over/in front of/within striking distance of plenty of hots without realizing it, and then seeing the snake later. I'm sure it has happened plenty of times without EVER seeing the snake and knowing it.

I think it goes to show that many snakes, especially venomous snakes, have a bad reputation that they don't deserve, and that they certainly don't want to have to use a defensive strike.

I'm a little jealous, though I'm sure the experience was scary. I still have yet to see my first rattler in the wild!