The Upper Geyser Basin Boardwalk Walk

The Upper Geyser Basin holds the densest concentration of geysers on Earth — roughly 150 of them within about a square mile — and a flat boardwalk runs through the middle of it. There is almost no climbing and no route-finding. The whole walk is about 8 km of level planks and paved path, and it is one of the great days out in any national park.

The rhythm of the day is set by the geysers, not by you. Rangers post predicted eruption windows for several of the large ones at the visitor center; plan your loop around those, and expect to sit and wait.

Staying on the boardwalk is not a suggestion — leaving it can kill you. The ground here is a thin mineral crust over water at roughly 93 °C, the local boiling point, and in places that crust covers voids you cannot see from above. It does not look dangerous. Bare, pale ground beside the planks looks exactly like ground. Several people have died in Yellowstone after falling through into hot springs, and others have been very badly burned; the water is not only near-boiling but chemically aggressive, and in the more acidic basins remains have not been recoverable. There is no rescue that arrives fast enough. Keep children within arm’s reach, keep pets out entirely, and do not step off the planks for a photograph — this is the single rule that matters here.

Getting there. Old Faithful sits on the park’s lower loop road, reached most easily from the West Entrance. The basin has a large visitor center with eruption predictions, water, and toilets.

Good to know:

Most park roads close to cars from around early November until spring — dates vary by entrance — so this walk is effectively a May-to-September outing. In deep winter the basin is reached only by snowcoach or snowmobile.
The basin sits above 2,200 m and is fully exposed; bring sun protection, and layers for cold mornings even in July.
Afternoons are busiest. An early start puts you on quiet boardwalks with steam hanging in the cold air.

Day 1

Old Faithful, the geyser boardwalks, and Black Sand Basin

Old Faithful Visitor Education Center → Old Faithful Visitor Education Center 8 km ↑ 40 m

Navigate this day

The standard basin circuit: watch Old Faithful, walk the boardwalk out past the big predictable geysers to Morning Glory Pool, then return and add the short Black Sand Basin loop.

Segments

Old Faithful 0.5 km ↑ 0 m 📍 Map

Old Faithful Visitor Education Center → Old Faithful viewing area

Paved path and benched boardwalk

Check the predicted eruption window posted inside, then take a seat on the boardwalk ring. Old Faithful is famous for being predictable, not punctual: the gap between eruptions varies widely — very roughly an hour to nearly two — and rangers forecast the next one from the length of the last, usually within about ten minutes. Allow an hour with the wait.

About this place

Old Faithful is a cone geyser in Yellowstone National Park in Wyoming, United States. It was named in 1870 during the Washburn–Langford–Doane Expedition and was the first geyser in the park to be named. It is a highly predictable geothermal feature, erupting on average every 92 minutes, with the period between eruptions ranging from as short as 35 minutes to as long as 120 minutes. The geyser and the nearby Old Faithful Inn are part of the Old Faithful Historic District.
Read more on Wikipedia ↗
Photo: Dietmar Rabich · CC BY-SA 4.0
Castle and Grand geysers 1.2 km ↑ 10 m 📍 Map

Old Faithful viewing area → Grand Geyser

Flat boardwalk over sinter

Head north across the basin to Castle Geyser, whose huge geyserite cone — built up over a very long time and likened to a castle — makes it the most striking structure here; it erupts at long intervals, on the order of half a day. Just beyond stands Grand Geyser, the tallest predictable geyser known, which fires in bursts from a pool rather than a cone. About 30 minutes' walking.

About this place

Castle Geyser is a cone geyser in the Upper Geyser Basin of Yellowstone National Park. It is noted for the particularly large geyserite sinter deposits, which form its cone. These deposits have been likened in appearance to a castle.
Read more on Wikipedia ↗
Photo: Brocken Inaglory: Brocken Inaglory · CC BY-SA 3.0
Along the Firehole River to Riverside Geyser 1 km ↑ 10 m 📍 Map

Grand Geyser → Riverside Geyser

Boardwalk beside the river

Follow the boardwalk along the Firehole River to Riverside Geyser, which sits on the bank and arcs its column out over the water — the most photogenic eruption in the basin, and another that rangers predict. About 20 minutes.

About this place

Riverside Geyser is a geyser in Yellowstone National Park in the U.S. state of Wyoming.
Read more on Wikipedia ↗
Morning Glory Pool and back 2.3 km ↑ 10 m 📍 Map

Riverside Geyser → Old Faithful area

Flat boardwalk and paved trail

Continue to the far end of the basin for Morning Glory Pool, a hot spring named for the flower it once resembled. Its colours shifted after decades of visitors threw coins and debris into the vent, partly clogging it — the pool is a monument to what crowds do to a fragile thing. Return the way you came. About 1 hour.

About this place

Morning Glory Pool is a hot spring in the Yellowstone Upper Geyser Basin of the United States. The spring is also known by the name Morning Glory Spring.
Read more on Wikipedia ↗
Photo: Wikimedia Commons · Public domain
Black Sand Basin loop 3 km ↑ 10 m 📍 Map

Old Faithful area → Old Faithful Visitor Education Center

Paved connector and short boardwalk loop

A short, often-skipped satellite group just west of Old Faithful, named for the dark obsidian sand in its runoff channels and worth the detour for Emerald Pool and Sunset Lake. Walk or drive the connector, loop the boardwalk, and close the day back at the visitor center. About 1 hour on foot.

About this place

The geothermal areas of Yellowstone include several geyser basins in Yellowstone National Park as well as other geothermal features such as hot springs, mud pots, and fumaroles. The number of thermal features in Yellowstone is estimated at 10,000. A study that was completed in 2011 found that a total of 1,283 geysers have erupted in Yellowstone, 465 of which are active during an average year. These are distributed among nine geyser basins, with a few geysers found in smaller thermal areas throughout the Park. The number of geysers in each geyser basin are as follows: Upper Geyser Basin (410), Midway Geyser Basin (59), Lower Geyser Basin (283), Norris Geyser Basin (193), West Thumb Geyser Basin (84), Gibbon Geyser Basin (24), Lone Star Geyser Basin (21), Shoshone Geyser Basin (107), Heart Lake Geyser Basin (69), other areas (33). Although famous large geysers like Old Faithful are part of the total, most of Yellowstone's geysers are small, erupting to only a foot or two. The hydrothermal system that supplies the geysers with hot water sits within an ancient active caldera. Many of the thermal features in Yellowstone build up sinter, geyserite, or travertine deposits around and within them.
Read more on Wikipedia ↗
Photo: Mav at English Wikipedia · CC BY-SA 3.0