Location: Wyoming, Idaho, and Montana
Established: March 1, 1872
Size: 2,221,766 acres
Yellowstone is a geological smoking gun that illustrates how violent the Earth can be. One event overshadows all others: Some 640,000 years ago, an area many miles square at what is now the center of the park suddenly exploded. In minutes the landscape was devastated. Fast-moving ash flows covered thousands of square miles. At the center only a smoldering caldera remained, a collapsed crater 45 by 30 miles. At least two other cataclysmic events preceded this one. Boiling hot springs, fumaroles, mud spots, and geysers serve as reminders that another could occur.
Yellowstone, however, is much more than hot ground and gushing steam. Located astride the Continental Divide, most of the park occupies a high plateau surrounded by mountains and drained by several rivers. Park boundaries enclose craggy peaks, alpine lakes, deep canyons, and vast forests. In 1872, Yellowstone became the world’s first national park, the result of great foresight on the part of many people about our eventual need for the solace and beauty of wild places.