In the parks planning stage, Tom Sawyer Island was called Mickey Mouse Island and was home to the Mickey Mouse Club and the Mouseketeers. Walt soon changed his mind, partly because Tom Sawyer was more appropriate for Frontierland, but mostly to insure, should the park go belly-up, the Mickey would not be associated with the failure. This was also the reasoning behind the decision to have Tinkerbell, not Mickey, introduce the
Disneyland TV series every week.
I swear, Walt was the smartest man alive when it came to thinking about the future and things like that.