We get a lot of questions about Yellowstone National Park, and the answers often surprise people. Here are some of our favorite facts and figures about the world’s first national park — good trivia for the road trip, too.

History & Firsts

Road Map of Yellowstone

• Yellowstone was established March 1, 1872 — making it the world’s first national park.
• The park’s boundaries have changed several times over the years: May 26, 1926; March 1, 1929; April 19, 1930; and October 20, 1932.
• It was designated a Biosphere Reserve in 1976 and a World Heritage Site on September 6, 1978.
• The park holds approximately 1,600 archeological sites, with more than 24 sites, landmarks, and districts on the National Register of Historic Places, plus one National Historic Trail.
• More than 900 historic buildings call the park home, along with thousands of books (many rare) and roughly 90,000 historic photographs.

By the Numbers

Road Map of Yellowstone

• The park covers 3,472 square miles — larger than Delaware and Rhode Island combined — spanning 63 miles north to south and 54 miles east to west.
• Wyoming, Montana, and Idaho all claim a portion of the park: 96% in Wyoming, 3% in Montana, and 1% in Idaho.
• The Greater Yellowstone Area encompasses 12 million acres and includes Grand Teton National Park, the John D. Rockefeller, Jr. Memorial Parkway, seven National Forests, and three National Wildlife Refuges.
• About 5% of the park is covered by water, 15% by grassland, and 80% by forest.
• Annual precipitation ranges from 10 inches at the north boundary to 80 inches in the southwest corner.
• Temperatures swing widely: Mammoth averages 9°F in January and 80°F in July (record high 99°F in 2002), while the West Entrance at Riverside Station recorded a low of -66°F in 1933.

Geothermal Facts

• Yellowstone sits on an active volcano. The park records an estimated 1,000 to 3,000 earthquakes every year.
• It’s home to more than 10,000 hydrothermal features, including over 300 active geysers.
• The Yellowstone Caldera is one of the world’s largest, measuring roughly 45 by 30 miles.
• Yellowstone’s geology is still changing today: a hydrothermal explosion at Biscuit Basin on June 13, 2026 carved new vents and a boiling pool into the landscape. Biscuit Basin remains closed to visitors following the explosion — check current park conditions before you go.

See the park’s geysers and hot springs for yourself — explore our guide to Yellowstone’s hot springs or the Yellowstone National Park attractions page.

Water & Waterfalls

Grand Canyon of the Yellowstone River

• Yellowstone has approximately 290 waterfalls that are 15 feet or higher, and they flow year-round.
• The tallest waterfall in the front country is the Lower Falls of the Yellowstone River, measuring 308 feet.
• Yellowstone Lake covers 131.7 square miles with 141 miles of shoreline, measuring 20 miles north to south and 14 miles east to west. Average depth is 140 feet, with a maximum of 410 feet.

Wildlife & Plants

Bitterroot Flowers

• 67 species of mammals call the park home, including 7 native ungulates and 2 species of bears.
• 322 species of birds have been recorded, 148 of which nest in the park.
• 16 species of fish (5 non-native), 6 species of reptiles, and 4 species of amphibians round out the wildlife count.
• The Canada lynx is the park’s one threatened species; the resident gray wolf (delisted and relisted in 2008) is its one endangered species.
• Plant life includes 7 species of conifers (lodgepole pine makes up about 80% of the park’s forest), roughly 1,150 native vascular plant species, 210+ non-native species, and 186 species of lichen.

Want a closer (and safer) look at Yellowstone’s wildlife? Visit the Grizzly & Wolf Discovery Center or check out our guide to wildlife viewing and birdwatching.

Visiting Yellowstone Today

Slough Creek Trail

• Yellowstone welcomed 4,762,988 visitors in 2025 — its second-highest year on record.
• The park has 5 entrances and 466 miles of roads, 310 miles of which are paved.
• Facilities include 9 visitor centers/museums/contact stations, 9 hotels and lodges with 2,000+ rooms and cabins, 12 campgrounds (7 run by the NPS and 5 by concessionaires) with more than 2,100 combined sites, 52 picnic areas, and 1 marina.
• Trail lovers can choose from more than 15 miles of boardwalk and roughly 1,000 miles of backcountry trails, with 92 trailheads and 301 backcountry campsites.

Ready to hit the trails yourself? Check out our guide to hiking and biking near West Yellowstone.

Frequently Asked Questions

What are some fun facts about Yellowstone National Park?
Yellowstone was the world’s first national park, sits atop an active volcano with more than 10,000 hydrothermal features, and is home to 67 mammal species — including two kinds of bears. At 3,472 square miles, it’s larger than Delaware and Rhode Island combined.

What is an interesting fact about Yellowstone National Park?
Yellowstone’s geology is still changing in real time. As recently as June 2026, a hydrothermal explosion at Biscuit Basin carved brand-new vents and a boiling pool into the landscape — proof the park’s geothermal “plumbing” is very much active today.

Is Yellowstone really sitting on an active volcano?
Yes. The Yellowstone Caldera is one of the largest active volcanic systems in the world, and the park records an estimated 1,000 to 3,000 earthquakes every year as a result.

As you can easily see, there is something for everyone to be found in the park. Whether your interests are geology, historic buildings, hiking, boating, camping, or just relaxing amid the wonder of nature, you will find what you are looking for at our first national park. Ready to plan your visit? Find a place to stay in West Yellowstone and start building your trip today.

All photos courtesy of Yellowstone National Park.

AUTHOR: SUSIE KNAPP