Jellystone Park is celebrating its 100th anniversary, however it may be for the last time, because attendance is down and Mayor Brown wants to close the park and sell the land. If the park is closed, Yogi Bear and Boo Boo will lose their home. They join forces with Ranger Smith to save Jellystone from closing forever. Yogi must really prove in this endeavor that he is "smarter than the average bear".

Jesse Aarons trained all summer to become the fastest runner in school, so he's very upset when newcomer Leslie Burke outruns him and everyone else. Despite this and other differences, including that she's rich, he's poor, and she's a city girl, he's a country boy, the two become fast friends. Together, they create Terabithia, a land of monsters, trolls, ogres, and giants and rule as king and queen. This friendship helps Jess cope with the tragedy that makes him realize what Leslie taught him.