Yellowstone National Park

Yellowstone is unlike any other national park because it sits atop one of the largest active volcanic systems in the world. Beneath the park lies the Yellowstone Caldera, a massive volcanic depression measuring approximately 30 by 45 miles (48 by 72 kilometers). This caldera was formed during a colossal volcanic eruption about 631,000 years ago, the most recent of three major "super-eruptions" that have shaped the Yellowstone Plateau over the past 2.1 million years. Although often referred to as a "supervolcano," Yellowstone is not expected to erupt anytime soon. Instead, the heat generated deep beneath the Earth's surface fuels the park's incredible hydrothermal activity, creating more than 10,000 geothermal features, including approximately half of the world's active geysers.

Among Yellowstone's most famous geothermal attractions is Old Faithful, one of the world's most predictable geysers, erupting approximately every 60 to 110 minutes. Nearby, the vibrant Grand Prismatic Spring dazzles visitors with brilliant bands of blue, green, yellow, orange, and red created by heat-loving microorganisms known as thermophiles. The park also features steaming fumaroles, bubbling mud pots, colorful hot springs, and powerful geyser basins that demonstrate the incredible forces constantly shaping Yellowstone's landscape.

Beyond its geothermal wonders, Yellowstone's scenery is equally breathtaking. Visitors can explore the dramatic Grand Canyon of the Yellowstone, where the Yellowstone River plunges over the spectacular Upper and Lower Falls, with the Lower Falls dropping an impressive 308 feet (94 meters)—nearly twice the height of Niagara Falls. Vast alpine meadows, dense lodgepole pine forests, crystal-clear lakes, rugged mountain ranges, and winding rivers create a diverse landscape that changes dramatically with the seasons.

Wildlife is one of Yellowstone's greatest attractions. The park is home to the largest concentration of mammals in the lower 48 states, including free-roaming American bison, elk, gray wolves, grizzly bears, black bears, moose, pronghorn, bighorn sheep, mountain goats, coyotes, river otters, and over 300 species of birds, including bald eagles, osprey, trumpeter swans, and peregrine falcons. The reintroduction of gray wolves in 1995 remains one of the most successful wildlife conservation efforts in modern history and has significantly influenced the park's ecosystem.