15 Things You Might Not Know About Yellowstone National Park

Celebrated for its flora, fauna, geological structures, and sprawling landscapes, Yellowstone National Park is undoubtedly one of the United States’s greatest centers of natural beauty. But there's more to this park than Old Faithful—and here are 15 highlights of the park, which celebrates its 150th anniversary on March 1, 2022.

1. Yellowstone is the world's second oldest national park.

The official date of establishment of Yellowstone National Park was March 1, 1872, making it the first park of its kind to earn the designation in North America. While Yellowstone is sometimes heralded as the oldest national park on Earth, it is 96 years younger than Mongolia’s Bogd Khan Uul.

2. Half of the world's geothermal features are located in Yellowstone.

One of the park’s most popular attractions is its collection of geothermal features, an umbrella term that includes geysers, hot springs, fumaroles, mudpots, and travertine terraces. With tens of thousands of such phenomena, Yellowstone is home to more than half of the world’s supply of geothermal features and approximately 60 percent of the world’s geysers. The park has an estimated 1283 geysers spread across nine geyser basins.

3. Nobody believed early witnesses of Yellowstone's geysers.

John Colter, a member of the Lewis and Clark Expedition, spent the winter of 1807 and 1808 on a solo journey through the wilderness of what is now Wyoming. Colter tried to share stories of what he had seen, but details of his travels describing a land of “fire and brimstone” were widely rebuffed as delusions. Almost 50 years later, independent explorer Jim Bridger returned from Yellowstone with accounts of boiling springs and waters sprouting from the ground—his reports met the same skepticism that dogged Colter.

4. The largest geyser in the world is in Yellowstone (and it's not the one you're thinking of).

Old Faithful, located in the Upper Geyser Basin, may be the most famous geyser on the planet, and for good reason: The punctual, easily calculated intervals between eruptions have earned it global celebration. But Old Faithful’s cousin in the Norris Geyser Basin trumps it in terms of sheer size. The Steamboat Geyser, which is capable of producing 300-foot-high eruptions of water, is the tallest active geyser on the planet.

5. Yellowstone National Park may be fatal to bison.

After more than a century of benign activity, in 2004 the geysers of the Norris Geyser Basin earned a toxic reputation when their emissions were deemed responsible for killing five roaming bison. Park scientists determined that a meteorological anomaly provoked an unusually high—and ultimately fatal—concentration of the basin’s fumes at ground level. Prior to this grisly moment, the last major mass gas fatality was in 1899, when several grizzly bears suffered a similar fate.

6. That said, the bison population remains intact.

Yellowstone is home to America’s oldest and largest natural herd of bison.

7. Initially, the U.S. Army was stationed at Yellowstone.

In 1882, avowed nature lover and Civil War hero General Philip Sheridan led an expedition that took him to Yellowstone. While Sheridan was duly impressed with the park’s aesthetic wonder, he was aghast at the presence of monopolist organizations running amok throughout the territory at the expense of the land.

After Congress stripped away funding for Yellowstone, he dispatched Captain Moses Harris, a Union soldier who had served under Sheridan and who shared his ecological ideologies, to lead troops to Yellowstone, protecting it against commercial poaching, the spread of wildfire, and maladies of all kinds. The armed forces stood guard over the park until 1918, when the establishment of the National Park Service usurped the military’s involvement with Yellowstone. The rangers that took the soldiers’ positions were known as “spread eagle men.”

8. Yellowstone boasts the largest supervolcano in the U.S.

The contiguous United States has more than its share of supervolcanoes—that is, volcanoes capable of producing more than 240 cubic miles of ejecta per eruption—with noteworthy examples living in California and New Mexico. But outweighing the pair is the Yellowstone Caldera: 45 miles long, 34 miles wide, and with a main magma chamber several times the size of the Grand Canyon. Though considered an active supervolcano, the caldera’s last eruption was 640,000 years ago.

9. Yellowstone experiences thousands of earthquakes every year.

A typical year sees between 1000 and 3000 earthquakes hit Yellowstone National Park. In January 2010, for instance, the park sustained 250 quakes in just two days. However, the vast majority of these tremors are so gentle they go completely unnoticed by human visitors.

10. A rare and mysterious flower grows in Yellowstone National Park.

Nowhere in the world but in the lakeshores of Yellowstone National Park does the (aptly named) Yellowstone Sand Verbena grow. What’s particularly strange about the anomaly is that its genetic makeup would suggest that it’s suited to warmer climates.

11. Some of the most primitive bacteria on the planet live in Yellowstone.

Another rare species that calls Yellowstone its home can be found thriving amid the gaseous emissions of the park’s hot springs. A particular strain of microbe, among the most primitive of any extant species, feeds off the area’s plentiful carbon dioxide and hydrogen resources.

12. The U.S. government eradicated—and then restored—Yellowstone's wolf population.

In the 1910s, Congress grew nervous about Yellowstone’s hunting wolves. Fearing that the predatory prowess of the park’s lupine population would result in an extinction of the local elk and other ungulates, Congress funded a systematic killing of any and all wolves inhabiting the area. Between 1914 and 1926, the act resulted in the elimination of 136 wolves, rendering Yellowstone virtually free of its apex predator. Unfortunately, Congress hadn’t prepared for the hike in prevalence of sick and lame animals, formerly the easiest targets for preying wolves.

Forty years later, the government began to have a change of heart. Congress met with biologists concerned about the threat of elk overpopulation, discussing the merits in reintroducing wolves into their former habitat. The debate ended in 1995 when the government began transporting gray wolf packs to the Yellowstone grounds. Data collected in 2005 reflected a healthy recovery of the wolf population in and around the Yellowstone area.

13. Yellowstone is the subject of a legal anomaly.

All Yellowstone National Park territory falls under the legal jurisdiction of the United States District Court for the District of Wyoming. However, only 96 percent of Yellowstone falls within Wyoming state lines; the remaining four percent is split between Montanan and Idahoan lands. This makes Wyoming’s the only district court to oversee land in more than one state. The park's wonky jurisdiction make it a potential setting for getting away with the perfect crime.

14. Yellowstone National Park has its own judicial system.

The previous point is more than just legal trivia. While Yellowstone offers a treasure trove of spectacles that any visitor should make a point to see, the park’s jail isn’t a must-see destination. As of 2006, Yellowstone boasts its own justice system, which includes a courtroom, presiding judge, and four holding cells. Furthermore, major crimes that occur on park grounds fall under the legal jurisdiction of one specifically assigned FBI Agent.

15. Yellowstone is home to the most remote location in the contiguous U.S.

Thirty-two miles separates any road, residence, or establishment from the ironically named Thorofare area, which earns it designation as the most isolated location in all of continental America. While hikers and campers are welcome to explore the grounds, which traverse both Yellowstone National Park and the Teton Wilderness, visitors are forbidden from tarnishing its rustic beauty with electrical devices or automobiles. The only way to get there is by horseback or, if you’ve got the energy, your own two feet.

A version of this article originally ran in 2015; it has been updated for 2022.