Thank you all for the responses so far. Crypto, I'm afraid it is true that access to the upper deck isn't wheelchair accessible. We did attempt several designs to make it so early on, but the budget just isn't there to do it, both in terms of construction time and money. That doesn't mean you can't make up to the upper deck, only that getting up there will take a measure of creativity on your part, something I've experienced here you have a great deal of. And the interior of the tree at ground level is still very accessible, very shady, and very roomy.
You are the first to note the reference to Winnie the Pooh. Great Job! In the beginning designs, I was aiming towards something that looked like an amalgamation of Winnie the Pooh and Piglet's tree, a storybook playhouse come to life on the playa. Of course, the design ended up going through a lot of phases and filters and the end project looks less than similar to our initial aim, but if you look close at the conceptual drawings, we left in windows (we'll make them out of stained glass) going up the trunk of the tree. I love the name Trespassers Will, the way it sounds, and the possible ideas the title might provoke it each citizen. Does 'will' mean 'allow', indicate some kind of response (as in Trespassers will be shot), or does it refer to our Will? I don't know...I just like the way it sounds.