Prepare to find them, as Hooker said, "all over", then be prepared to get them out of there. If you are parked at the top, and bringing them up is the "rule" rather than the exception, you will need some "mechanical advantage" or strong legs and youthful back.
I use mechanical advantage by way of a three-fold purchase aluminum block and tackle with 200 feet of 3/8-inch climber's rope. 3-fold purchase allows 1/3 the deer's weight as the required input. I pull down hill - the deer goes up hill. Pretty simple and very easy on the back.