What is the Greater Yellowstone Ecosystem?
"Yellowstone National Park forms the core of the Greater Yellowstone Ecosystem. At 34,375 square miles, it is one of the largest nearly intact temperate-zone ecosystems on Earth. Greater Yellowstone’s diversity and natural wealth includes the hydrothermal features, wildlife, vegetation, lakes, and geologic wonders like the Grand Canyon of the Yellowstone River." - U.S. National Park Service