- For other uses of the term, see Mountain Zone (disambiguation).
Sonic finally makes it to Dr. Eggman's helicopter and Tails is happy to see him. Eggman, however, isn't too thrilled to see his archenemy and Sonic asks Eggman what's he planning. Eggman replies that all he needs to say is that there is only one Chaos Emerald left and leaves. Tails tells Sonic that Eggman may be trying to gather all of the Emeralds for his next plan and urges Sonic that they must get the last Emerald before he does. Tails says that the final Chaos Emerald is on top of Angel Island knowing Eggman is heading there next and Sonic races off to the scene.
The Zone consists of three acts followed by a boss fight against Dr. Eggman at the end of the third act. If the player reaches the goal with at least fifty Rings, they will receive a fragment of the yellow Chaos Emerald.