Created in 1872, Yellowstone was the very first national park in the world. It is the centerpiece of the 20 million acre Greater Yellowstone Ecosystem, a region that includes Grand Teton National Park and adjacent National Forests. Considered to be the world's largest intact ecosystem in the northern temperate zone, Yellowstone is well-known for its wildlife and is the most popular megafauna location in the Continental United States, occupied by grizzly bears, wolves, bison and elk. It is located primarily in Wyoming but extends into Montana and Idaho.
Yellowstone has many types of ecosystems, including subalpine forest, mountain ranges, canyons, lakes and rivers. The topography has been shaped by lava flows and volcanic rocks from the still-active Yellowstone Caldera, the largest sup