How Big Is Yellowstone Park?

How Big Is Yellowstone Park? At 3,472 square miles—over 2.2 million acres—Yellowstone is larger than the states of Rhode Island and Delaware combined. How big is Yellowstone compared to a state? Yellowstone is bigger than two U.S. states. At 3,472 square miles—over 2.2 million acres—Yellowstone is larger than the states of Rhode Island and Delaware