I have hunted a piece of public land in south east OH before which is riddled with horse trails that are still heavily used all the way through gun season. I was amazed at how much they don't care about those paths. The closest got to the trail was about 50 yards, with a bow, several times i had deer in front of me when a person on a Horse would walk by and the deer would just stop and watch them without moving a muscle. one time the deer was within ten yards of the trail nearly in full vision and the three people on the horse never saw it. They grow so accustom to horses and the voices that come with them that they know to be catious around them but don't really pay them much mind. Actually come to think of it I never saw one run from a person on a horse.