I've climbed several trees over the 20" recommendation. I have found that it is very hard to get the climber to move if the tree is over 24". There is one that I climb a good bit that is just shy of 25", and it is quite difficult to get my first pull up on the bottom section. After that, it works ok...it'll about wear me out getting that first one done, tho. As ThunderChicken stated, if my cables will fit it, I'll try it. It takes a pretty big tree to get over 24" in diameter. I'd guess you would be able to find a climbable tree in there. Good luck!