Where is the cloaca on a snake?

The cloaca - is located at the base of the tail. If you look at the scale pattern on the underside of the snakes body, the scales are primarily rectangular in shape, and lined up side-by-side (think of it like a ladder) - these are the ventral scales. Towards the tail, the pattern changes to shorter, more rounded scales. The junction between the two patterns is the snake's cloaca.