Yellowstone National Park in Wyoming. (Alamy)

Happy birthday, Yellowstone.

It’s been 144 years since Ulysses S. Grant established the United States’ first national park at the headwaters of the Yellowstone River in Wyoming, “For the benefit and enjoyment of the people.”

Yellowstone is still one of the largest national parks in the world, certainly the largest in the United States, and is among the nation’s five most visited parks with about 3.5 million people coming and going each year.

The Interior Department, which manages the park through the National Park Service, celebrated Tuesday with a blog that boasted about its hotness. Namely, it’s the site of a supervolcano.

In 1870, two years before the area was pressed into service as a park, 30-year-old Army Lt. Gustavus Doane climbed to the top of Mount Washburn and noticed a gap in a strip of Rocky Mountains. Doane thought there could only be one explanation, Washington Post reporter Joel Achenbach wrote for National Geographic last year: “The great basin,” Doane wrote, “has been formerly one vast crater of a now extinct volcano.” He was correct.

Half of the hydrothermal features in the entire world are found within the park, about 10,000 — “an extraordinary collection of hot springs, mudpots, fumaroles… and — of course — geysers,” Interior wrote. Heat-craving microorganisms known as thermophiles live in those areas, giving Yellowstone its pretty bright colors.


Steam rises from the Sapphire Pool at Biscuit Basin in Yellowstone National Park. (Brad Ohlund/MacGillvray Freeman Films)

The park’s biggest draw is arguably Old Faithful, a geyser that blows water and steam skyward more than 15 times per day. But the park lays claim to one of the largest active volcanoes in the world. Its first major eruption two million years ago blew ash over nearly 600,000 square miles, a fact that has fueled a few doomsday scenarios from speculators who worry that it might be primed to erupt again.

The last lava flow, Interior said, was 70,000 miles ago. The U.S. Geological Survey, University of Utah and the park service created the Yellowstone Volcano Observatory near the turn of the century to keep an eye on it.

Although the U.S. government preserved and recognized the area as a park more than a century ago, Native Americans have a far longer relationship, dating back 11 million years, long before that eruption.

In addition to its impressive collection of hot spots, Yellowstone is home to the largest collection of mammals in the contiguous United States — 67 species, including grizzly bears, elk, moose and fox. There are also about 300 species of birds, 16 types of fish.