Slim, I used to go 20-30 feet up, until I bounced a couple of arrows off of shoulder blades. I had a pro tell me the same thing. They sure won't know you're there, but that's a terrible angle. Twelve to fifteen feet has worked pretty well for me in Maryland. Shot my nicest buck, a 2 1/2 year old ten pointer, with my feet ten feet off the ground, and he was ten yards from the tree. Tagged out last year by shooting a six point and a nine point within fifteen minutes of each other from twelve feet up, 7 and 8 yards away.