Yellow Stone National Park

Yellowstone Sits on Top of a Supervolcano That Will Eventually Erupt

That is not an exaggeration for effect. The Yellowstone hotspot – the magma chamber beneath the park – produced eruptions approximately 2.1 million, 1.3 million, and 640,000 years ago. The cycle suggests the next major eruption is overdue in geological time, though current seismological monitoring shows no indication of imminent activity. What the hotspot produces in the meantime is the largest concentration of geothermal features on earth: more than 10,000 hydrothermal features, more than half the world’s active geysers, springs in cobalt, turquoise, yellow, and orange, and ground temperatures in some areas hot enough to kill within minutes. Combined with the megafauna – bison, grizzly bears, grey wolves reintroduced in 1995 and now a successful breeding population, elk in the thousands – Yellowstone is unlike any national park on earth.

Fee Changes for 2026

Starting January 1, 2026, international visitors (including Canadian citizens) pay an additional USD 100 per person on top of the standard USD 35 seven-day vehicle pass. This makes the total entry cost USD 135 per international adult, a significant increase from previous years. US residents pay USD 35 per vehicle (not per person) for a seven-day pass.

Old Faithful and the Upper Geyser Basin

Old Faithful erupts every 44-125 minutes (interval varies), reaches 30-55 metres, and lasts 2-5 minutes. The eruption prediction board at the visitor centre is usually accurate to within 10 minutes. It is genuinely impressive, not overrated, and worth timing your first morning around.

Old Faithful is surrounded by the Upper Geyser Basin, which contains more than a quarter of all the world’s geysers within about one square mile. Morning Glory Pool is 15 minutes’ walk from Old Faithful and has colours (deep blue to turquoise to green to orange at the edges) that look digitally enhanced but are produced by different heat-tolerant bacteria at different temperature gradients. Castle Geyser, Grand Geyser, and Riverside Geyser are all within walking distance and all worth watching.

Grand Prismatic Spring

The Grand Prismatic Spring in the Midway Geyser Basin is 113 metres across and 50 metres deep – the largest hot spring in the United States. The aerial view showing concentric rings of colour (the photographs everyone knows) is available from the overlook trail; the boardwalk at water level gives a different, more immediate perspective.

Lamar Valley

For wildlife, Lamar Valley in the park’s northeast is the priority. Bison herds of several hundred animals are routine. Wolves are regularly spotted with binoculars from the road at dawn. Grizzly bears are seen with enough frequency that roadside backups form. Get there before 08:00. Bring binoculars. The valley is sometimes called “America’s Serengeti” and, in terms of accessible megafauna density, the comparison holds.

Mammoth Hot Springs

The travertine terraces at Mammoth change constantly as springs activate and go dormant. Some are brilliantly white; others orange or grey-brown. The complex is open year-round; in winter the frozen formations are particularly dramatic. Elk wander the town of Mammoth throughout the year and are essentially street animals.

Staying

Old Faithful Inn (1904 log structure) is the most famous and most requested lodge; book 6 months to a year ahead for summer. Canyon Lodge and Mammoth Hotel are alternatives. Outside the park, West Yellowstone is the main gateway town; Jackson Hole to the south has excellent restaurants and access to Grand Teton National Park, at higher prices.

May and October are the most underrated times to visit: smaller crowds, hotel prices 30-50% lower than summer, and highly active wildlife. Download offline maps before entering – cell service is unreliable throughout most of the park.