Geography and Overview of Yellowstone National Park

An Overview of Yellowstone's History, Geography, Geology, Flora and Fauna

Two young girls watch as Old Faithful is Erupting
Two young girls watch as Old Faithful is Erupting.


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Yellowstone is the United States' first national park. It was established on March 1, 1872 , by President Ulysses S. Grant. Yellowstone is mainly located in the state of Wyoming, but it also extends into Montana and a small part of Idaho. It covers an area of 3,472 square miles (8,987 sq km) that is made up of various geothermal features like geysers, as well as mountains, lakes, canyons, and rivers. The Yellowstone area also features many different types of plants and animals. 

History of Yellowstone National Park

The history of humans in Yellowstone dates back to around 11,000 years ago when Indigenous groups began to hunt and fish in the region. It is believed that these early humans were a part of the Clovis culture and used the obsidian in the region to make their hunting weapons, mainly Clovis tips, and other tools. 

Some of the first explorers to enter the Yellowstone region were Lewis and Clark in 1805. During their time spent in the area, they encountered several Indigenous communities such as the Nez Perce, Crow, and Shoshone. In 1806, John Colter, who was a member of the Lewis and Clark expedition, left the group to join fur trappers - at which point he came across one of the park's geothermal areas. 

In 1859 some early explorations of Yellowstone took place when Captain William Reynolds, a U.S. Army surveyor, began exploring the northern Rocky Mountains. Exploration of the Yellowstone area was then interrupted due to the beginning of the Civil War and did not officially resume until the 1860s.

One of the first detailed, explorations of Yellowstone occurred in 1869 with the Cook-Folsom-Peterson Expedition. Shortly thereafter in 1870, the Washburn-Langford-Doane Expedition spent a month surveying the area, collecting different plants and animals and naming unique sites. Following that expedition, Cornelius Hedges, a writer, and lawyer from Montana who had been a part of the Washburn expedition suggested making the region a national park. 

Although there was much action to protect Yellowstone in the early 1870s, serious attempts to make Yellowstone a national park did not occur until 1871 when geologist Ferdinand Hayden completed the Hayden Geological Survey of 1871. In that survey, Hayden gathered a complete report on Yellowstone. It was this report that finally convinced the United States Congress to make the region a national park before it was bought by a private landowner and taken away from the public. On March 1, 1872, President Ulysses S. Grant signed the Act of Dedication and officially created Yellowstone National Park. 

Since its founding, millions of tourists have visited Yellowstone. In addition, roads, several hotels like the Old Faithful Inn and visitor centers, such as the Heritage and Research Center, have been constructed within the park's boundaries. Recreational activities like snowshoeing, mountaineering, fishing, hiking, and camping are also popular tourist activities in Yellowstone.

Yellowstone's Geography and Climate

96% of Yellowstone's land is within the state of Wyoming, while 3% is in Montana and 1% is in Idaho. Rivers and lakes make up 5% of the park's land area and the largest body of water in Yellowstone is Yellowstone Lake, which covers 87,040 acres and is up to 400 feet (120 m) deep. Yellowstone Lake has an elevation of 7,733 feet (2,357 m) which makes it the highest altitude lake in North America. The remainder of the park is mostly covered by forest and a small percentage of grassland. Mountains and deep canyons also dominate much of Yellowstone.

Because Yellowstone has variations in altitude, this determines the park's climate. Lower elevations are milder, but in general summers in Yellowstone average 70-80°F (21-27°C) with afternoon thunderstorms. Yellowstone's winters are normally very cold with highs of just 0-20°F (-20- -5°C). Winter snow is common throughout the park.

Geology of Yellowstone

Yellowstone was initially made famous due to its unique geology caused by its location on the North American plate, which for millions of years has slowly moved across a mantle hotspot via plate tectonics. The Yellowstone Caldera is a volcanic system, the largest in North America, which has formed as a result of this hot spot and subsequent large volcanic eruptions.

Geysers and hot springs are also common geologic features in Yellowstone which have formed due to the hotspot and geologic instability. Old Faithful is Yellowstone's most famous geyser but there are 300 more geysers within the park.

In addition to these geysers, Yellowstone commonly experiences small earthquakes, most of which are not felt by people. However, large earthquakes of magnitudes 6.0 and greater have struck the park. For example in 1959 a magnitude 7.5 earthquake hit just outside the park's boundaries and caused geyser eruptions, landslides, extensive property damage and killed 28 people.

Yellowstone's Flora and Fauna

In addition to its unique geography and geology, Yellowstone is also home to many different species of plants and animals. For example, there are 1,700 species of trees and plants native to the Yellowstone area. It is also home to many different species of fauna- many of which are considered megafaunas such as grizzly bears and bison. There are around 60 animal species in Yellowstone, some of which include the gray wolf, black bears, elk, moose, deer, bighorn sheep and mountain lions. Eighteen species of fish and 311 species of birds also live within Yellowstone's boundaries.
To learn more about Yellowstone visit the National Park Service's Yellowstone page.


National Park Service. (2010, April 6). Yellowstone National Park (U.S. National Park Service). Retrieved from:

Wikipedia. (2010, April 5). Yellowstone National Park - Wikipedia, the Free Encyclopedia. Retrieved from:

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Briney, Amanda. "Geography and Overview of Yellowstone National Park." ThoughtCo, Feb. 16, 2021, Briney, Amanda. (2021, February 16). Geography and Overview of Yellowstone National Park. Retrieved from Briney, Amanda. "Geography and Overview of Yellowstone National Park." ThoughtCo. (accessed March 26, 2023).