"Our national heritage is richer than just scenic features; the realization is coming that perhaps our greatest national heritage is nature itself, with all its complexity and its abundance of life, which, when combined with great scenic beauty as it is in the national parks, becomes of unlimited value." — George Wright, Joseph Dixon, and Ben Thompson, Fauna of the National Parks of the United States (1933)
Established in 1872, it was the first national park in the United States, and perhaps the world. Its geological and biological wonders have led international groups to declare it a world heritage site and a biosphere reserve. Yellowstone National Park captures the spirit and purpose of the National Park Service, blending modern and ancient human history with nature in its raw complexity.
Covering 3,468 square miles (8983 square kilometers) in Wyoming, Idaho, and Montana, Yellowstone National Park is larger than the states of Delaware and Rhode Island. It is a place of superlatives, sheltering the oldest and largest bison herd in the United States and the largest supervolcano on the planet.
The Operational Land Imager (OLI) on the Landsat 8 satellite acquired a natural-color image of Yellowstone on June 9, 2013. In the images at the top of this page, the Landsat data have been overlaid on a digital elevation model created with data from the ASTER instrument on NASA's Terra satellite. The model gives a three-dimensional sense of the landscape. The photograph below from the National Park Service shows a section of Yellowstone Canyon.
Most of the landscape here is the product of intense volcanic activity in the not-too-distant past. Two eruptions between 1.2 million and 600,000 years ago each ejected more than 1,000 cubic kilometers (240 cubic miles) of molten material, making them two of the largest volcanic eruptions in Earth's geologic record. The region is pockmarked with several calderas, many of them now filled with lake water. The volcanic plumbing beneath the park is still active, giving energy to more than ten thousand hot springs, mud pots, terraces, and geysers—most famously, Old Faithful.
The Yellowstone, Snake, and other rivers have cut deep channels and canyons through the volcanic deposits over thousands of years. The rugged, mountainous terrain gives rise to at least 290 waterfalls taller than 5 meters (15 feet). The largest is the Lower Falls of the Yellowstone, where water drops 94 meters (308 feet).
Much of the park is covered by subalpine forests, mostly lodgepole pine. Sagebrush steppe, alpine meadows, and grasslands also provide food and habitat for more then 360 species. The most charismatic are the elk, bighorn sheep, and bison, which run in some of the largest wild herds in the world. Grizzly bears and wolves also make homes in the park, a relative rarity in the lower 48 United States.
Humans have enjoyed the fruits of this land for at least 11,000 years. Digging through more than a thousand sites, archaeologists have found evidence of the Clovis people and other Native American tribes. Tools and arrowheads made of rock from Yellowstone's Obsidian Cliff have been found throughout the park, but also throughout wide swaths of North America, suggesting an ancient trade in these tools created in Yellowstone.
In the summer of 1988, fires caused by lightning and humans consumed vast stretches of Yellowstone. An estimated 793,000 of the park's 2,221,800 acres burned in that brutal summer. You can view a time-series of images showing the evolution of the park after the fires in World of Change: Burn Recovery in Yellowstone.
- National Park Service (2016) Yellowstone National Park. Accessed April 16, 2016.
- NASA Earth Observatory (2012, January 4) Fire and the Future of Yellowstone.
- NASA Earth Observatory (2011, December 8) Satellites Track Yellowstone's Underground Heat.
- NASA Earth Observatory (2008, November 30) Old Faithful.
- NASA Earth Observatory (2005, September 5) Yellowstone Lake, Wyoming.
NASA Earth Observatory images by Joshua Stevens, using Landsat data from the U.S. Geological Survey and ASTER GDEM data from NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. Photograph courtesy of the National Park Service. Caption by Mike Carlowicz.