After locusts devastate the Great Vally and turn it into a wasteland, the inhabitants of the Great Vally agreed to move out in search of food to eat. The locusts however have destroyed the surrounding area, leaving no food in sight. After wandering without food the herd begins to argume and threaten to split. The little dinosaur friends: Littlefoot (Brandon Lacroix), Cera (Anndi McAfee), Ducky (Aria Noelle Curzon), Petrie (Jeff Bennett) and Spike (Rob Paulsen) don't want this to happen and take it upon themselves to search for food. They embark on a long journey to find food. They eventually come to the edge of the ocean and see an island that is alive with vegetation and is connected to the mainland by a thin land bridge. While crossing the land bridge an earthquake occurs they reach safety on the island, but the earthquake has destroyed the land bridge therefore trapping them on the island. Eventually they run into an old friend Chomper (Cannon Young) who they met a long time ago. The events eventually lead up to the gang meeting a water dinosaur which agrees to take them across the ocean, which saddens their friend. The are reunited with their families who in the meantime found a new home until the Great Vally restores itself.