
Yellowstone officially became the first national park in the United States in 1872. Not only is it home to all kinds of wild animals, but it also features a variety of impressive natural phenomena, including hot springs, geysers, and an active supervolcano.
Most people have heard of Yellowstone National Park. However, there’s still a lot that the average person doesn’t know about this incredible travel destination.
Listed below are 17 fascinating facts that every traveler should keep in mind about the country’s first national park.
It Spans Three States
Yellowstone National Park spans almost 3,500 square miles and is spread out over Wyoming (96%), Montana (3%), and Idaho (1%).
It Predates Statehood
Eighteen years before Wyoming and Idaho were granted statehood and 17 years before Montana became a state, Yellowstone was officially named a national park.
It’s Named for the Yellowstone River
This park gets its name from the yellow sandstone that’s found along eastern Montana’s Yellowstone River.
It Has Over 1,800 Archaeological Sites
Approximately 1,850 archeological sites are located throughout Yellowstone National Park.
It’s Full of Waterfalls and Hiking Trails
Yellowstone is home to hundreds of waterfalls (including 45 named waterfalls) and approximately 900 miles of hiking trails.
Sixty-Seven Mammals Reside Here
Sixty-seven different species of mammals reside in Yellowstone National Park, along with 300 different types of birds and 16 different types of fish.
Bison Have Always Been Here
Since prehistoric times, bison have congregated in the Yellowstone area.
It’s Home to a Supervolcano
A supervolcano with the potential for a magnitude eight eruption is located in Yellowstone National Park. It’s had three massive eruptions, and the most recent was 2.1 million years ago.
Magma Is Close to the Surface
Magma sits just three to eight miles below the Sour Creek Dome and eight to 12 miles below the Mallard Lake Dome.
Earthquakes Are Common Occurrences Here
Between 700 and 3,000 earthquakes occur in Yellowstone each year, but most of them are too small to notice.
It Preserves Thousands of Hydrothermal Features
Over 10,000 hydrothermal features, including geysers and hot springs, are preserved within the borders of Yellowstone National Park.

Microorganisms Provide Its Color
The stunning colors seen throughout Yellowstone’s geysers and hot springs come from trillions of heat-loving microorganisms known as thermophiles.
Old Faithful Has Become Less Faithful
The Old Faithful geyser got its name for its highly reliable eruptions. Over the last few years, though, it’s become more unpredictable. It may be less predictable, but Old Faithful still erupts about 17 times per day, so it’s worth checking out.
The Hot Springs Can Dissolve a Body
Yellowstone’s hot springs are very hot and very acidic. They can even dissolve a human body in just one day!
Temperatures Fluctuate a Lot
The temperatures in Yellowstone fluctuate dramatically throughout the year, falling as low as -66 degrees Fahrenheit (-54 degrees Celsius) in the winter and rising to 99 degrees Fahrenheit (37 degrees Celsius) during the summer.
It Used to Feature Garbage-Eating Bears
Until World War II, one of Yellowstone’s attractions featured bears eating the park’s trash.
It’s Close to Another National Park
Grand Teton National Park (Wyoming) is just 10 miles from Yellowstone, but it still takes more than an hour to get there.