Middle Fork or Main I sleep out every chance I get.
I even kicked a rattler out of "my" spot one night on the MF and slept like a baby. I did piss in a circle around my sleeping zone, but I was below the high water mark for those purists amongst.
That said I would not pick a spot near a big pile of rocks or large log piles, the kind of place that a snake would love to come out of.
I am usually about 10 feet off the bow of my boat cuz I am a lazy, retired guide and don't want to carry my shit any further than that.