After finding a mysterious message carved in a special tree, Li'l Jack and Daddy explore parks in Green Country (Tulsa, Oklahoma) to find a similar tree. Li'l Jack learns how to recognize trees by their physical traits: height, bark texture, seeds and leaves, and also visits the Creek Council Oak, under which Tulsa was founded during a meeting of Creek Tribal leaders. But when they have difficulty finding a tree quite like their special Blackjack Oak, they visit the Cross Timbers - a place where some of the oldest Blackjacks grow in Oklahoma. Li'l Jack learns why there are so few Blackjacks left, and how he can grow one of his very own.