Yellowstone National Park, established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872, is a national park located primarily in the U.S. state of Wyoming, though it also extends into Montana and Idaho. Yellowstone was the first national park in the world, and is known for its wildlife and its many geothermal features, especially Old Faithful Geyser, one of the most popular features in the park. It has many types of ecosystems, but the subalpine forest is dominant.Yellowstone National Park spans an area of 3,468.4 sq mi (8,983 km2), comprising lakes, canyons, rivers and mountain ranges. Yellowstone Lake is one of the largest high-altitude lakes in North America and is centered over the Yellowstone Caldera, the largestsupervolcano on the continent. The caldera is considered an active volcano. It has erupted with tremendous force several times in the last two million years. Half of the world's geothermal features are in Yellowstone, fueled by this ongoing volcanism. Lava flows and rocks from volcanic eruptions cover most of the land area of Yellowstone. The park is the centerpiece of the Greater Yellowstone Ecosystem, the largest remaining, nearly intact ecosystem in the Earth's northern temperate zone. |
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Hundreds of species of mammals, birds, fish and reptiles have been documented, including several that are either endangered or threatened. The vast forests and grasslands also include unique species of plants. Yellowstone Park is the largest and most famous mega fauna location in the Continental United States. Grizzly Bears, wolves, and free-ranging herds of bison and elk live in the park. The Yellowstone Park Bison Herd is the oldest and largest public bison herd in the United States. |
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Geological characteristics form the foundation of an ecosystem. In Yellowstone, the interplay between volcanic, hydrothermal, and glacial processes and the distribution of flora and fauna are intricate and unique. The topography of the land from southern Idaho northeast to Yellowstone results from millions of years of hotspot influence. Some scientists believe the Yellowstone Plateau itself is a result of uplift due to hotspot volcanism. |
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Yellowstone National Park is the centerpiece of the 20 million acre/31,250 square-mile (8,093,712 ha/80,937 km2) Greater Yellowstone Ecosystem, a region that includes Grand Teton National Park, adjacent National Forests and expansive wilderness areas in those forests. The ecosystem is the largest remaining continuous stretch of mostly undeveloped pristine land in the continental United States,considered to be the world's largest intact ecosystem in the northern temperate zone (although the area is mostly not temperate but subalpine, and all the national forest lands surrounding the National Park are not intact). With the successful wolf reintroduction program, which began in the 1990s, virtually all the original faunal species known to inhabit the region when white explorers first entered the area can still be found there. |
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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. There are 290 waterfalls of at least 15 feet (4.5 m) in the park, the highest being the Lower Falls of the Yellowstone River at 308 feet (94 m).Two deep canyons are located in the park, cut through the volcanic tuff of the Yellowstone Plateau by rivers over the last 640,000 years. The Lewis River flows through Lewis Canyon in the south, and the Yellowstone River has carved the colorful Grand Canyon of the Yellowstone in its journey north.
The park is the core of the Greater Yellowstone Ecosystem, one of the largest intact temperate zone ecosystems remaining on the planet. Black bears, grizzly bears, deer, elk, bison, bighorn sheep and wolves can all be found within the park borders. Geothermal features include geysers, mud pots, hot springs, fumaroles, and others. This is all because of the active volcano that Yellowstone sits on top of. Geothermal features are formed from superheated water heated by the volcano. The pressure is so intense that it gets released into the air as hundreds of gallons of steaming water, or, when the pressure is not as intense, hot springs or mud pots are formed. Various colors of the pool are due to different types of bacteria growing in different temperatures.
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The most famous geyser in the park, and perhaps the world, is Old Faithful Geyser, located in Upper Geyser Basin, where Castle Geyser, Lion Geyser and Beehive Geyser are considered ones of the most beautiful geysers in the world; the park also contains the largest active geyser in the world—Steamboat Geyser in the Norris Geyser Basin. There are 300 geysers in Yellowstone and a total of at least 10,000 geothermal features altogether. Half the geothermal features and two-thirds of the world’s geysers are concentrated in Yellowstone.Yellowstone experiences thousands of small earthquakes every year, virtually all of which are undetectable to people. There have been six earthquakes with at least magnitude 6 or greater in historical times, including a 7.5 magnitude quake that struck just outside the northwest boundary of the park in 1959. This quake triggered a huge landslide, which caused a partial dam collapse on Hebgen Lake; immediately downstream, the sediment from the landslide dammed the river and created a new lake, known as Earthquake Lake.
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Yellowstone is at the northeastern end of the Snake River Plain, a great U-shaped arc through the mountains that extends from Boise, Idaho some 400 miles (640 km) to the west. This feature traces the route of the North American Plate over the last 17 million years as it was transported by plate tectonics across a stationary mantle hotspot. The landscape of present-day Yellowstone National Park is the most recent manifestation of this hotspot below the crust of the Earth.The Yellowstone Caldera is the largest volcanic system in North America. It has been termed a "supervolcano" because the caldera was formed by exceptionally large explosive eruptions. The current caldera was created by a cataclysmic eruption that occurred 640,000 years ago, which released 240 cubic miles (1,000 km³) of ash, rock and pyroclastic materials. This eruption was 1,000 times larger than the 1980 eruption of Mount St. Helens. It produced a crater nearly a two thirds of a mile (1 km) deep and 52 by 28 miles (84 by 45 km) in area and deposited the Lava Creek Tuff, a welded tuff geologic formation. The most violent known eruption, which occurred 2.1 million years ago, ejected 588 cubic miles (2,450 km³) of volcanic material and created the rock formation known as the Huckleberry Ridge Tuff and created the Island Park Caldera. A smaller eruption ejected 67 cubic miles (280 km³) of material 1.2 million years ago, forming the Henry's Fork Caldera and depositing the Mesa Falls Tuff.
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Wildfire is a natural part of most ecosystems, and plants found in Yellowstone have adapted in a variety of ways.Douglas-fir has a thick bark which protects the inner section of the tree from most fires. Lodgepole Pines —the most common tree species in the park— generally have cones that are only opened by the heat of fire. Their seeds are held in place by a tough resin, and fire assists in melting the resin, allowing the seeds to disperse. Fire clears out dead and down wood, providing fewer obstacles for lodgepole pines to flourish. Subalpine Fir, Engelmann Spruce, Whitebark Pine and other species tend to grow in colder and moister areas, where fire is less likely to occur. Aspen trees sprout new growth from their roots, and even if a severe fire kills the tree above ground, the roots often survive unharmed because they are insulated from the heat by soil. The National Park Service estimates that in natural conditions, grasslands in Yellowstone burned an average of every 20 to 25 years, while forests in the park would experience fire about every 300 years. |
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Yellowstone climate is greatly influenced by altitude, with lower elevations generally found to be warmer year round. The record high temperature was 99 °F (37 °C) in 2002, while the coldest temperature recorded is −66 °F (−54 °C) in 1933. During the summer months of June through early September, daytime highs are normally in the 70 to 80 °F (21 to 27 °C) range, while nighttime lows can go to below freezing (0 °C)—especially at higher altitudes. Summer afternoons are frequently accompanied by thunderstorms. Spring and fall temperatures range between 30 and 60 °F (-1 and 16 °C) with cold nights in the teens to single digits (−5 to −20 °C). Winter in Yellowstone is very cold with high temperatures usually between zero to 20 °F (−20 to −5 °C) and nighttime temperatures below zero °F (−20 °C) for most of the winter.
Precipitation in Yellowstone is highly variable and ranges from 15 inches (380 mm) annually near Mammoth Hot Springs, to 80 inches (2,000 mm) in the southwestern sections of the park. The precipitation of Yellowstone is greatly influenced by the moisture channel formed by the Snake River Plain to the west that was, in turn, formed by Yellowstone itself. Snow is possible in any month of the year, with averages of 150 inches (3,800 mm) annually around Yellowstone Lake, to twice that amount at higher elevations.
Tornadoes in Yellowstone are rare; however, on July 21, 1987, the most powerful tornado recorded in Wyoming touched down in the Teton Wilderness of Bridger−Teton National Forest and hit Yellowstone National Park. Called the Teton–Yellowstone tornado, it was classified as an F4, with wind speeds estimated at between 207 and 260 miles per hour (333 and 420 km/h). The tornado left a path of destruction 1 to 2 miles (1.6 to 3.2 km) wide, and 24 miles (39 km) long, and leveled 15,000 acres (6,100 ha; 23 sq mi) of mature pine forest.
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Picnicking in Yellowstone National Park has long been a favorite activity for park goers. The Mount Washburn Trail has long been a favorite. This 2-mile walk through the upper forests eventually gives way to a sweeping view of the park below. At the top, visitors can unpack their lunch and enjoy the scenery while they munch. Be sure to pack out everything you pack in. The beauty of Yellowstone Park relies on the responsibility of its visitors, so never leave trash behind. The Lonestar Geyser is another great place to picnic. You can watch the Geyser or stroll around the surrounding area. Though there are favorite places to picnic, some of the fun of a trip to Yellowstone is exploring, so do not be afraid to pack your lunch and find your own favorite place to picnic.
