Yellowstone, established in 1872 as the world's first national park, sits directly atop a supervolcano whose last major eruption, some 640,000 years ago, was thousands of times more powerful than Mount St. Helens, the geysers, hot springs, and mudpots visible today are surface expressions of that same underlying magma chamber, still very much active beneath the park.
Geysers and Hydrothermal Features
Old Faithful, erupting roughly every 90 minutes, remains the park's most famous sight, but the nearby Grand Prismatic Spring (the largest hot spring in the US, its rainbow colours produced by heat-loving bacteria) is, by most visitors' accounts, even more visually striking, best viewed from an overlook trail above rather than at ground level.
The park holds roughly half of all the world's active geysers, concentrated in a handful of basins connected by boardwalks that keep visitors safely away from the fragile, scalding-hot ground.
Wildlife Valleys
Lamar Valley, often called America's Serengeti, offers some of the best wildlife viewing in the lower 48 states, wolves (reintroduced in 1995 after being eradicated), bison, elk, and grizzly bears are all regularly spotted, particularly at dawn and dusk.
Hayden Valley, along the Yellowstone River, is another reliable wildlife viewing area, especially for bison herds that move through in large numbers during certain seasons, sometimes stopping traffic entirely as they cross the park roads.
Recommended Stay · Yellowstone · Upper Geyser Basin
Old Faithful Inn
A historic log-built lodge dating to 1904, directly overlooking Old Faithful geyser, with a soaring log-beamed lobby considered an architectural landmark in its own right.
