Yellowstone National Park and the volcanic heart of Yellowstone

Yellowstone National Park in Yellowstone sits over a vast supervolcano, where geysers, canyons and forests share one high plateau shaped by fire and ice.

Yellowstone National Park is a vast high-altitude landscape in the Rocky Mountains of the United States, centred on the Yellowstone Plateau and shaped by intense volcanic and glacial forces. Created as a national park on 1 March 1872 under President Ulysses S. Grant, it extends across parts of Wyoming, Montana and Idaho in an elevated basin ringed by mountain ranges and cut by major rivers.

A national park built on a supervolcano

The defining fact of Yellowstone National Park is that the entire protected area sits atop the Yellowstone hotspot, one of the most powerful volcanic systems on Earth and a recognised supervolcano. Large areas of the park are covered by rhyolite lava flows and related volcanic rocks from eruptions in the late Pliocene and Quaternary periods, giving the plateau its broad, gently undulating forms and distinctive light-coloured bedrockrhyolite plateau. The most prominent volcanic structure is the Yellowstone Caldera, a huge depression formed around 640,000 years ago during the Lava Creek Tuff eruption, which expelled immense volumes of material and reshaped the regionYellowstone Caldera dimensions.

The Yellowstone Plateau lies at an average elevation of about 2,400 m (7,875 ft), forming part of the continental divide between Pacific and Atlantic drainage systemsaverage elevation. Around the plateau, mountain ranges such as the Gallatin Range in the northwest, the Absaroka Range to the east and the northern extremity of the Teton Range to the south-west rise several hundred metres higher, enclosing the park in a high mountain frameencircling mountain ranges. This setting places Yellowstone National Park firmly within the Middle Rocky Mountains Physiographic Province, with terrain that has been compressed, uplifted, eroded and glaciated across roughly 150 million years.

Geysers, hot springs and a colourful caldera lake

The volcanic engine beneath Yellowstone National Park feeds one of the densest concentrations of hydrothermal features on the planet. Water from rain and snowmelt percolates down through fractured rock, becomes superheated above the magma body and returns to the surface as geysers, hot springs, mud pots and fumaroles. Among these features, Old Faithful Geyser has become a symbol of the park as a regularly erupting geyser that vents columns of hot water and steam from the Upper Geyser BasinOld Faithful and geyser basins. Nearby, the Grand Prismatic Spring stands out as the largest hot spring in Yellowstone, spanning about 110 m (370 ft) across and 37 m (121 ft) deep, with vivid bands of colour created by minerals and thermophilic microorganisms.

Hydrothermal activity is spread across multiple basins on the caldera floor, each with its own patterns of geyser eruptions, boiling pools and steaming ground. These features sit among forests, meadows and river valleys, giving Yellowstone National Park a distinctive mixture of geothermal landscapes and more familiar mountain sceneryhydrothermal concentration. Yellowstone Lake, a high-elevation lake covering part of the Yellowstone Caldera, is one of the largest lakes of its altitude in North America and occupies a broad basin on the central plateauYellowstone Lake description. Around it, river systems such as the Yellowstone River cut deep canyons through volcanic and sedimentary rocks, exposing layers of colour that contrast sharply with the surrounding forest.

From the first national park to a protected Rocky Mountain ecosystem

Yellowstone National Park holds a central place in conservation history as the area designated in 1872 as the world’s first national park under United States federal lawYellowstone establishment in 1872. The Yellowstone National Park Protection Act, signed by Ulysses S. Grant on 1 March 1872, set aside a large tract of land in the Rocky Mountains to preserve its geothermal features, wildlife and landscapes. The protected area now covers more than 8,900 km² (about 3,472 square miles), with over nine tenths of its land in Wyoming and smaller portions in Montana and Idahocurrent park area.

Geologically, the park forms part of the Greater Yellowstone Ecosystem, a region where tectonic movements, repeated volcanism, glacial advances and retreat, and continuous erosion have built and modified mountains, canyons and plateausgeologic processes. Pre-Tertiary sedimentary and metamorphic rocks appear in the northern parts of the park, recording ages from the Precambrian through the Cretaceous and representing nearly every Paleozoic and Mesozoic system apart from the Silurianolder rock record. The modern protected area therefore brings together very young volcanic deposits and much older crustal rocks inside one boundary.

Visiting Yellowstone National Park: what travellers from Western Europe should know

• Yellowstone National Park lies mainly in north-western Wyoming in the United States, with smaller sections in southern Montana and eastern Idaho, and is reached by road networks from surrounding towns.
• The terrain within the park consists of a high plateau at around 2,400 m (7,875 ft) with surrounding mountain ranges, deep river canyons and areas of unstable geothermal ground, so many paths involve gradients and uneven surfaces.
• Major features such as geyser basins, river canyons and Yellowstone Lake are spread across a large area, and visiting them involves travel by vehicle combined with walks on designated trails.
• The official language is English and the currency is the United States dollar.
• Entry requirements depend on your nationality; UK travellers can check the FCDO travel advice at gov.uk/foreign-travel-advice, Irish travellers the Department of Foreign Affairs at ireland.ie.

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Frequently asked questions about Yellowstone National Park

Where is Yellowstone National Park located?

Yellowstone National Park lies mainly in north-western Wyoming in the United States, with smaller portions in Montana and Idaho in the Rocky Mountains.

What should travellers expect on a visit to Yellowstone?

Travellers encounter a high plateau landscape with geyser basins, hot springs, large lakes, river canyons and surrounding mountain ranges, all within a large protected area.

What makes Yellowstone National Park distinctive among national parks?

Yellowstone National Park is distinctive because it was established in 1872 as the world’s first national park and sits directly over an active supervolcano with extensive hydrothermal features.