The beginning of the global conservation movement

Yellowstone National Park, USA, World Heritage Site

America bison, Yellowstone


Established in 1872, Yellowstone National Park is the world's first legally established national park and considered the “father” that started the modern global movement in conservation. Located in Wyoming, Montana and Idaho, it is home to a large variety of wildlife including grizzly bears, wolves, bison, and elk. Preserved within Yellowstone National Park are Old Faithful and a collection of the world's most extraordinary geysers and hot springs, and the Grand Canyon of the Yellowstone. Administered by the US Parks Service, Yellowstone was designated an International Biosphere Reserve in 1976, and a World Heritage Site in 1978. The park has more than 1,000 cultural sites with Obsidian Cliff and five buildings designated as National Historic Landmarks. With its hot springs, geyser basins, lava formations, lakes, waterfalls, rivers and river canyons, it is a place of unrivalled beauty - a place to study volcanic forces and heat flow within the earth.

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Size and location

The vast natural forest of Yellowstone National Park covers nearly 9,000 km2; 96% of the park lies in Wyoming, 3% in Montana and 1% in Idaho, USA.

Natural formations

Centerpiece of the Greater Yellowstone Ecosystem, the largest remaining, nearly intact ecosystem in the Earth's northern temperate zone, Yellowstone contains half of the world's known geothermal features and the world's largest concentration of geysers (more than 300). The most famous geyser in the park is Old Faithful which erupts approximately every 91 minutes. It also contains the largest active geyser in the world—Steamboat Geyser. Yellowstone sits on top of a hotspot where a thermal plume or column of molten rock rises from deep within the earth and feeds into a large chamber 11,000 feet below the earth's surface. The heat from this molten rock in the chamber warms water from rain and snow that seeps down; steam and hot water rise to the surface, forming hot springs and geysers. Most of Yellowstone’s land is covered with lava flows and rocks from volcanic eruptions. There are also 290 waterfalls, the highest being the Lower Falls of the Yellowstone River (94 m), three deep canyons created by rivers including the Grand Canyon of the Yellowstone and the Black Canyon of the Yellowstone in its journey north and the largest high-altitude lakes in North America, Yellowstone Lake.

Flora and fauna

The vast forests and grasslands include unique species of plants. Yellowstone National Park has one of the world's largest petrified forests, trees which were long ago buried by ash and soil and transformed from wood to mineral materials. Over 1,700 species of trees and other vascular plants are native to the park. Another 170 species are considered to be exotic species. Of the eight conifer tree species, Lodgepole Pine forests cover 80% of the total forested areas. Other conifers, such as subalpine fir, Engelmann spruce, Rocky Mountain Douglas-fir and whitebark pine, are found in scattered groves throughout the park. As of 2007, 7% of the whitebark pine is threatened by a fungus known as white pine blister rust but mostly in forests well to the north and west. Quaking Aspen and willows are the most common species of deciduous trees.

Dozens of species of flowering plants have been identified, most of which bloom between the months of May and September. The Yellowstone sand verbena is a rare flowering plant found only in Yellowstone. In Yellowstone's hot waters, bacteria form mats of bizarre shapes consisting of trillions of individuals. These bacteria are some of the most primitive life forms on earth. Other bacteria in the Yellowstone hot springs may also prove useful to scientists who are searching for cures for various diseases.

Yellowstone is widely considered to be a 'mega fauna' wildlife habitat. There are almost 60 species of mammals in the park, including the gray wolf, the threatened lynx, and grizzly bears. Other large mammals include the bison (buffalo), black bear, elk, moose, mule deer, white-tailed deer, mountain goat, pronghorn, bighorn sheep and mountain lion. Bison once numbered between 30 and 60 million individuals throughout North America, and Yellowstone remains one of their last strongholds. Their populations had increased from less than 50 in the park in 1902 to 3,000 in 2008. The Yellowstone herd is believed to be one of only four free roaming and genetically pure herds on public lands in North America. From 1914 to 1935 to protect elk populations, the U.S. culled wolves in the park and nearly eliminated them. By the 1990s, the Federal government had reversed its views on wolves and 66 Mackenzie Valley wolves, imported from Canada, were reintroduced into the park. In 2008, 118 wolves could be found in the park and the U.S. Fish and Wildlife Service removed the Northern Rocky Mountain wolf population from the endangered species list.

Some 600 grizzly bears live in the Greater Yellowstone Ecosystem, more than half living within Yellowstone. The grizzly is currently listed as a threatened species, however the U.S. Fish and Wildlife Service has announced that they intend to take it off the endangered species list for the Yellowstone region but will likely keep it listed in areas where it has not yet recovered fully. Population figures for elk are in excess of 30,000—the largest population of any large mammal species in Yellowstone. The northern herd has decreased enormously since the mid-1990s; this has been attributed to wolf predation and other effects such as elk using more forested regions to escape predation, consequently making it harder for researchers to accurately count them. The northern herd migrates west into south-western Montana in the winter. The southern herd migrates southward, and is the largest mammalian migration remaining in the U.S. outside Alaska.

In 2003, the tracks of one female lynx and her cub were spotted. Other less commonly seen mammals include 25 mountain lions and an unknown number of wolverine. These uncommon and rare mammals provide insight into the health of Yellowstone and help guide decision making on how best to preserve habitats.

Eighteen native species of fish live in Yellowstone, including the core range of the Yellowstone cutthroat trout. Yellowstone is also home to six species of reptiles such as the painted turtle and Prairie rattlesnake, and four species of amphibians, including the Boreal chorus frog.

More than 300 bird species have been reported, almost half of which nest in Yellowstone. As of 1999, 26 pairs of nesting bald eagles have been documented. Extremely rare sightings of whooping cranes have been recorded, however, only three individuals are known to live in the Rocky Mountains, out of 385 known worldwide. Other birds, considered to be species of special concern because of their rarity in Yellowstone, include the common loon, harlequin duck, osprey, peregrine falcon and the trumpeter swan.


Invasive alien species (IAS) while most of them found in areas with the greatest human visitation, such as near roads and at major tourist areas, have also spread into the backcountry. The park has been implementing for many years, a programme to control and eradicate these invaders.

To combat the perceived threat of disease transmission (brucellosis) to cattle, national park personnel regularly move bison herds back into the park when they venture outside the borders. During the winter of 1996–97, the bison herd was so large that 1,079 bison that had left the park were shot or sent to slaughter to avoid brucellosis transmission to cattle. APHIS has stated that with vaccinations and other means, brucellosis can be eliminated from the bison and elk herds throughout Yellowstone.

The Yellowstone cutthroat trout has faced several threats since the 1980s including the suspected illegal introduction into Yellowstone Lake of lake trout, an invasive species which consumes the smaller cutthroat trout. Although lake trout were established in Shoshone and Lewis lakes in the Snake River drainage from U.S. Government stocking operations in 1890, it was never officially introduced into the Yellowstone River drainage. The cutthroat trout has also faced an ongoing drought, as well as the accidental introduction of a parasite which causes a terminal nervous system disease in younger fish. Since 2001, all native sport fish species caught in Yellowstone waterways are subject to a catch and release law.

Work area: 
Protected Areas
Protected Areas
World Heritage
Protected Areas
North America
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