There are some legal issues you should consider before you do anything to that cottonwood. First, is it protected in the community where it is growing? Second, do you know anything about limb or tree removal? Third, do you have an insurance policy to cover you? Fourth, do you have a signed written agreement with the property owner (not the renter) to alter the look of the tree, if you are not going to remove it entirely? Fifth, does the written agreement protect you if you damage the 1800's shed? People have a way of changing their mind after the damage is done and they see how the tree will look. If you do any cutting, you may out-balance the tree allowing normal winds to move the tree in different directions than at present. Might the tree blow down on some other desirable physical property? This might cause delayed liability issues for you. I think these issues are important whether the tree is in a housing subdivision or on a farm. I know a person who took bees out from behind a partial brick and wood exterior wall. The owner acknowledged that the mortar couldn't be matched and verbally agreed to the operation. When it was all over the mortar was white compared to the weathered mortar. The homeowner sued, won, and the beekeeper had to pay to remove the brick wall and have it reinstalled so that it looked the same throughout. Quite a cost for a large swarm of bees! James C. Bach [log in to unmask] [log in to unmask]