Elksnout- from my experience, turkeys will continue to use the same roosting trees unless they get too pressured... even if you scare the birds and they dont come back to same tree, they will normally roost within a couple hundreds yards of their original tree.. However, they could be gone for days if you scared them badly.. Yeah when you see a roosting tree you'll know it, should be droppings and feathers everywhere at the base of it.. Also, just go out early one morning and let out a crow call... most of the time they will gobble to that and then you can pinpoint their roost tree that way as well. And like already stated, later in the season they may have multiple roosting trees but it seems early in the season, they want to roost in the same spot every night.