Before the Matterhorn was constructed, the treehouse on Tom Sawyer Island was the "highest point in Disneyland", a fact that is mentioned on the early island maps, and also on the first version of the TSI poster. It doesn't look that high from the ground, but when you look at photos taken from that vantage point, you are definitely up there. Take a look at my post from August 15th to see for yourself!
I think every kid dreams of having a place like Tom Sawyer Island, with treehouses, trails, suspended rope bridges, caves, bottomless pits, and so on. It has been been rejiggered and dumbed down over the years in the name of safety (or something), and even in its current neutered state it is in danger of becoming another extinct attraction.
Just a note for everyone, I will be spending Thursday and Friday at Disneyland! Various members of my family, including my niece and two nephews (who have never been to the park before) will be there, and I am really looking forward to seeing everything through their eyes! I should be back posting vintage photos for you on Saturday. See ya!