World Heritage Identification Number: 28
World Heritage since: 1978
Category: Natural Heritage
WHE Type: Protected Areas & National Parks
Transboundary Heritage: No
Endangered Heritage: No
Country: 🇺🇸 United States of America
Continent: Americas
UNESCO World Region: Europe and North America
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Yellowstone National Park: America's First National Park
Yellowstone National Park, located primarily in the U.S. state of Wyoming, is a testament to the breathtaking beauty and diverse ecosystems that define North America. Established in 1872, it holds the distinction of being the world's first national park, setting a precedent for preserving pristine wilderness areas for future generations.
The park spans nearly 9,000 square kilometers, making it one of the largest protected areas in the contiguous United States. Its boundaries extend slightly into the neighboring states of Montana and Idaho, but the majority of the park lies within Wyoming. This expansive territory encompasses a wide range of habitats, from extensive subalpine forests and open meadows to towering mountain ranges and steaming geothermal landscapes.
One of the most striking features of Yellowstone is its abundance of geothermal activity. More than half of the world's known geothermal features can be found here, with over 10,000 examples scattered throughout the park. These include hot springs, mud pots, and the famous geysers, of which there are more than 500. Among these, Old Faithful Geyser remains the most iconic. While often thought to erupt hourly, its current average interval is approximately 90 to 94 minutes, with individual gaps ranging from 54 to 120 minutes.
In addition to its geothermal wonders, Yellowstone is renowned for its rich and varied wildlife. The park is home to numerous large mammals, including grizzly bears, wolves, bison, and elk, as well as smaller creatures like coyotes, beavers, and black bears. The park's diverse ecosystem supports a vibrant food chain, allowing visitors to witness the intricate balance between predator and prey.
The vegetation within Yellowstone is equally diverse, with subalpine forest being the most prevalent. This unique ecosystem is characterized by coniferous trees like whitebark pine, Engelmann spruce, and Douglas fir. The park's varied topography also supports other biomes, such as grasslands, wetlands, and alpine tundra.
Yellowstone National Park continues to see high visitor numbers, with over 4.5 million recreation visits in recent years, making it one of the most visited national parks in the United States. Visitors can explore the Visitors can explore the park’s many trails on foot or horseback, enjoy cycling on park roads, take guided tours, or simply enjoy scenic drives through this magnificent landscape. The park's visitor centers provide valuable information about the area's geology, wildlife, and history, ensuring that visitors leave with a deeper appreciation for the park's natural and cultural significance, including a long history of Indigenous presence.
In summary, Yellowstone National Park stands as a testament to the beauty and diversity of North American ecosystems. With its vast geothermal landscapes, rich wildlife, and stunning vistas, it remains a must-visit destination for nature enthusiasts and casual travelers alike. As the world's first national park, it continues to inspire conservation efforts and serve as a model for preserving our planet's most precious wild places.
UNESCO Description of the World Heritage Site
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. Yellowstone contains half of all the world's known geothermal features, with more than 10,000 examples. It also has the world's largest concentration of geysers (more than 300 geyers, or two thirds of all those on the planet). Established in 1872, Yellowstone is equally known for its wildlife, such as grizzly bears, wolves, bison and wapitis.
UNESCO Justification of the World Heritage Site
Criterion (vii): The extraordinary scenic treasures of Yellowstone include the world’s largest collection of geysers, the Grand Canyon of the Yellowstone River, numerous waterfalls, and great herds of wildlife.
Criterion (viii): Yellowstone is one of the world's foremost sites for the study and appreciation of the evolutionary history of the earth. The park has a globally unparalleled assemblage of surficial geothermal activity, thousands of hot springs, mudpots and fumaroles, and more than half of the world’s active geysers. Nearly 150 species of fossil plants, ranging from small ferns and rushes up to large Sequoia and many other tree species, have been identified in the park’s abundant fossil deposits. The world’s largest recognized caldera (45 km by 75 km – 27 miles by 45 miles) is contained within the park.
Criterion (ix): The park is one of the few remaining intact large ecosystems in the northern temperate zone of the earth. All flora in the park are allowed to progress through natural succession with no direct management being practiced. Forest fires, if started from lightning, are often allowed to burn where possible to permit the natural effects of fire to periodically assert itself. The park’s bison are the only wild, continuously free-ranging bison remaining of herds that once covered the Great Plains and, along with other park wildlife, are one of the greatest attractions.
Criterion (x): Yellowstone National Park has become one of North America's foremost refuges for rare plant and animal species and also functions as a model for ecosystem processes. The grizzly bear is one of the worlds’ most intensively studied and best-understood bear populations. This research has led to a greater understanding of the interdependence of ecosystem relationships.
Encyclopedia Record: Yellowstone National Park
Yellowstone National Park is a national park of the United States located in the northwest corner of the state of Wyoming, with small portions extending into Montana and Idaho. It was established by the 42nd U.S. Congress through the Yellowstone National Park Protection Act and signed into law by President Ulysses S. Grant on March 1, 1872. Yellowstone was the first national park in the US, and is also widely understood to be the first national park in the world. The park is known for its wildlife and its many geothermal features, especially the Old Faithful geyser, one of its most popular. While it represents many types of biomes, subalpine forest is the most abundant. It is part of the South Central Rockies forests ecoregion.Additional Site Details
Area: 898,349 hectares
Number of Components: 1
(viii) — Outstanding example representing major earth stages
(ix) — Outstanding example representing ecological and biological processes
(x) — Contains most important habitats for biodiversity
Coordinates: 44.46056 , -110.82778
IUCN World Heritage Outlook
The 2025 Conservation Outlook on Yellowstone National Park reports the following assessment:
Source: International Union for Conservation of Nature (IUCN) · View assessment
World Heritage Research
Discover scientific research and academic studies that deepen our understanding of Yellowstone National Park from its history and significance to its conservation, management, and contemporary challenges.
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Relationships among Birds, Willows, and Native Ungulates in and around Northern Yellowstone National Park
A threshold of tolerance for browsing exists among bird species in Yellowstone's riparian zones, beyond which both bird density and species richness decline significantly. This study, conducted across eight willow stands with varying levels of elk and moose browsing (ranging from 3.5% to 100% severely browsed willows), found that only two sites supported all five focal bird species (Common Yellowthroat, Lincoln's Sparrow, Warbling Vireo, Wilson's Warbler, and Yellow Warbler). The Lincoln's Sparrow was the only species present in all stands. Using data from 1989–1990, researchers measured bird densities and habitat structure variables, revealing that browsing intensity, shrub height heterogeneity, foliage density, and landscape factors (e.g., hydrology, adjacent community type) collectively shape bird assemblages. While browsing directly affects bird communities, predictive models incorporating broader ecological variables could improve accuracy.
Jackson, S. G. (1992). Relationships among Birds, Willows, and Native Ungulates in and around Northern Yellowstone National Park. Utah State University. https://doi.org/10.26076/2CC5-07AF
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Magma Intrusion and Volatile Ascent Beneath Norris Geyser Basin, Yellowstone National Park
A recent study reveals that the rapid uplift and subsidence observed near Norris Geyser Basin, Yellowstone National Park, are driven by evolving processes of deep magma intrusion followed by volatile ascent. The research, utilizing Global Positioning System (GPS) and interferometric synthetic aperture radar (InSAR) data, shows that between 1996–2001, deep magma intrusion occurred, which was later followed by the ascent and accumulation of volatiles at shallow depths—possibly as shallow as a few hundred meters. This shallow volatile accumulation has progressively shallowed from the 2014 to the 2016 deformation episodes, correlating with increased eruptions of Steamboat Geyser since March 2018. The study also highlights an elevated risk of hydrothermal explosions in this region due to the shallow nature of volatile accumulation.
Wicks, C. W., Dzurisin, D., Lowenstern, J. B., & Svarc, J. (2020). Magma Intrusion and Volatile Ascent Beneath Norris Geyser Basin, Yellowstone National Park. Journal of Geophysical Research: Solid Earth, 125(2). Portico. https://doi.org/10.1029/2019jb018208
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How climate impacts the composition of wolf‐killed elk in northern Yellowstone National Park
Climate significantly influences the composition of wolf-killed elk in northern Yellowstone National Park, affecting prey population dynamics. The study found that wolves are more likely to kill bulls or calves under specific climatic conditions, such as low snow water equivalent (SWE) and poor vegetation productivity, rather than cows—who are crucial for population reproduction. Over 20 winters, researchers monitored 17 wolf packs, analyzing the sex, age, and nutritional condition of elk kills in early and late winter periods. They discovered that summer plant productivity, SWE, and elk abundance interact to determine whether wolves target bulls, cows, or calves, with climate acting as a key mediator in predation patterns.
Wilmers, C. C., Metz, M. C., Stahler, D. R., Kohl, M. T., Geremia, C., & Smith, D. W. (2020). How climate impacts the composition of wolf‐killed elk in northern Yellowstone National Park. Journal of Animal Ecology, 89(6), 1511–1519. Portico. https://doi.org/10.1111/1365-2656.13200
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Relative Abundance of Thiolated Species of As, Mo, W, and Sb in Hot Springs of Yellowstone National Park and Iceland
Research reveals that thiolated species of arsenic (As), molybdenum (Mo), tungsten (W), and antimony (Sb) are prevalent in sulfide-rich hot springs, particularly in Yellowstone National Park and Iceland. Thioarsenates were the most abundant and widespread, often dominating arsenic speciation, while thiomolybdates also dominated in many Icelandic springs. Thiotungstates and thioantimonates were less frequent but still significant contributors. The study highlights that thiolation substantially influences the speciation of these elements, with higher sulfide-to-metal(loid) ratios leading to greater thiolation, especially in Icelandic systems. These findings underscore the necessity of analyzing thiolated species when studying geothermal environments, as traditional methods often overlook their presence.
Planer-Friedrich, B., Forberg, J., Lohmayer, R., Kerl, C. F., Boeing, F., Kaasalainen, H., & Stefánsson, A. (2020). Relative Abundance of Thiolated Species of As, Mo, W, and Sb in Hot Springs of Yellowstone National Park and Iceland. Environmental Science & Technology, 54(7), 4295–4304. https://doi.org/10.1021/acs.est.0c00668
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Gray wolf habitat use in response to visitor activity along roadways in Yellowstone National Park
Gray wolves in Yellowstone National Park adjust their habitat use in response to visitor activity, particularly along roadways. Research found that wolves tend to avoid areas closer to roads during the day and peak visitation periods, especially in summer, indicating a behavioral shift likely due to human presence. While prey availability did not significantly influence this pattern, the degree of road avoidance varied among wolf packs, with some becoming more tolerant to human activity—potentially increasing their vulnerability to human-related risks if they venture outside the park. The study used seasonal and diel-specific step selection functions (SSFs) to analyze these patterns from 1979 to 2017, providing insights that could guide adaptive management strategies to conserve natural wolf behavior amid rising visitation.
Anton, C. B., Smith, D. W., Suraci, J. P., Stahler, D. R., Duane, T. P., & Wilmers, C. C. (2020). Gray wolf habitat use in response to visitor activity along roadways in Yellowstone National Park. Ecosphere, 11(6). Portico. https://doi.org/10.1002/ecs2.3164
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Temperature impacts community structure and function of phototrophic Chloroflexi and Cyanobacteria in two alkaline hot springs in Yellowstone National Park
Temperature plays a key role in shaping the distribution and activity of phototrophic Chloroflexi alongside Cyanobacteria in alkaline hot springs, challenging previous assumptions that only temperature constrains these microbial communities. While phototrophic Cyanobacteria richness and oxygenic photosynthesis declined with increasing temperature, Chloroflexi maintained diversity and anoxygenic photosynthetic rates even at near the upper thermal limits (~72-73°C). This suggests niche differentiation among Chloroflexi taxa, potentially influenced by factors beyond temperature such as morphology or metabolic pathways. The study used 16S rRNA gene sequencing and photoassimilation microcosms to analyze samples from 45 to 72°C in two Yellowstone hot springs, revealing distinct temperature-driven distributions for Roseiflexus, Chloroflexus (Chloroflexi), and Leptococcus (Cyanobacteria). Carbon isotopic data further indicated shifting metabolic pathways with temperature. These findings highlight the resilience and adaptability of phototrophic Chloroflexi in extreme environments.
Bennett, A. C., Murugapiran, S. K., & Hamilton, T. L. (2020). Temperature impacts community structure and function of phototrophic Chloroflexi and Cyanobacteria in two alkaline hot springs in Yellowstone National Park. Environmental Microbiology Reports, 12(5), 503–513. Portico. https://doi.org/10.1111/1758-2229.12863
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Predatory fish invasion induces within and across ecosystem effects in Yellowstone National Park
The introduction of predatory lake trout into Yellowstone Lake triggered profound and far-reaching ecological changes, extending beyond the aquatic environment to impact terrestrial food webs. Over four decades (1972–2017), this invasion led to a dramatic decline in native prey fish, particularly Yellowstone cutthroat trout, while altering plankton assemblages within the lake and reducing nutrient transport to tributary streams. The effects crossed ecosystem boundaries, compelling grizzly and black bears to seek alternative foods and causing significant declines in osprey nest density and success. Bald eagles adjusted their diets to compensate for the loss of cutthroat trout, underscoring the cascading impacts of invasive species on pristine ecosystems. This study highlights how predatory fish introductions can disrupt multiple trophic levels, both within and across ecosystems.
Koel, T. M., Tronstad, L. M., Arnold, J. L., Gunther, K. A., Smith, D. W., Syslo, J. M., & White, P. J. (2019). Predatory fish invasion induces within and across ecosystem effects in Yellowstone National Park. Science Advances, 5(3). https://doi.org/10.1126/sciadv.aav1139
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