Biscuit Basin

 

After fully exploring the Upper Geyser Basin, we made a quick detour to Biscuit Basin, just a short distance away. While it doesn't rival the grandeur of the Upper Basin, it offers a pleasant boardwalk loop around a handful of small geysers.

The bridge across the Firehole River into Biscuit Basin appeared to be guarded by a “fierce beast”, though it was far more interested in grazing than intimidating passing visitors.

Just beyond the bridge, we spotted Black Opal Pool, the only black hot spring we encountered in Yellowstone.

The main highlights here are Wall Pool (above) and Sapphire Pool (below). Wall Pool, averaging around 88°C, is intensely hot and even boils in places.

Sapphire Pool, slightly cooler at about 77°C, also bubbles intermittently. Their extreme temperatures support thermophilic bacteria, which create the vivid blue tones that dominate both pools. Each has been shaped by past explosive events, leaving behind steep, dramatic walls that enhance their visual impact.

Other minor features include Avoca Spring (above) and Jewel Geyser (below), which resemble some of the smaller geysers found in the Upper Basin.

As a tip for future visitors, Biscuit Basin is best explored before the Upper Geyser Basin, otherwise, it can feel a little underwhelming by comparison.

Upper Geyser Basin - Old Faithful

 

Yellowstone’s most iconic attraction is undoubtedly the Upper Geyser Basin, home to the world-famous Old Faithful. This remarkable area contains the highest concentration of geysers on the planet. Click here for park map.

Castle Geyser

Among its many features is Castle Geyser, known for its massive sinter formation, though we unfortunately missed its eruption by just a few minutes.

Grand Geyser

Not long after, we witnessed the towering Grand Geyser erupting in powerful bursts up to 65 metres high. As it only erupts two or three times a day, we had carefully timed our visit, and it did not disappoint.

Turban Geyser

Nearby, Turban Geyser forms part of the same complex as Grand Geyser, offering a smaller but still impressive display.

Sawmill Geyser

Close by Grand Geyser, Sawmill Geyser proved to be one of the liveliest features in the basin. Though not the largest, its energetic eruptions sent jets of water up to 10 metres high, and it seemed to be constantly active as we passed throughout the day.

Tardy Geyser

Sawmill's neighbour, Tardy Geyser, is a smaller version that begins erupting shortly after Sawmill, hence the name.

Crested Pool

Along the boardwalk, we encountered three vividly coloured hot springs. Crested Pool stood out with its intense blue color, consistent high temperature, and dramatic boiling action that occasionally resembles a small geyser eruption.

Beauty Pool

Beauty Pool displayed a deep blue centre, surrounded by rings of green yellow and orange created by heat-loving thermophiles. The colours of the thermal pools are influenced by both temperature and mineral content with the hotter zones typically at the blue end of the spectrum. 

Chromatic Pool

Chromatic Pool is an anomaly, with stark white mineral deposits dominating the colours of the bacteria.

Firehole River

The crystal-clear Firehole River winds gracefully through the basin, weaving between geysers. While less dramatic than the geysers, it provides a vital lifeline for the surrounding ecosystem.

Grotto Geyser

During our visit, Grotto Geyser erupted continuously, sending powerful surges of water over its contorted sinter cone, likely formed around an ancient stand of trees. This was one of the more active geysers in the Basin during our visit.

Morning Glory Pool

One of the most visually striking features was Morning Glory Pool, perhaps the best example of Yellowstone’s vivid thermophilic colour gradients.

Old Faithful

We paused for lunch at the viewing area for Old Faithful, surrounded by a large crowd with the same idea.

Old Faithful stands as the world's most renowned geyser and the star attraction of Yellowstone's Upper Geyser Basin. True to its name, it erupts with remarkable consistency, sending powerful plumes of water and steam up to 40 meters high roughly every 90 minutes.

Lion Geyser

Lion Geyser quickly became one of our favourite sights in the basin. This impressive cone geyser frequently erupts on a similar schedule to Old Faithful, with a thundering roar, shooting a towering fountain up to 27 meters high. With viewing areas located nearby, the sheer power and sound of its eruptions feel even more thrilling than at Old Faithful.

Heart Spring

Although often overlooked beside the dramatic Lion Geyser (above background), Heart Spring is a quiet gem worth pausing to appreciate. This small by beautiful spring only exhibits the turquious blue hue.

Spasmodic Geyser

Spasmodic Geyser, with its intricate mineral formations and multiple vents, resembles a bubbling coral reef more than a traditional geyser. The intricate mineral deposits and multiple vents make it one of the more interesting in the Basin.

Old Faithful

As we passed Old Faithful on our way back to the car park, it treated us to a bonus farewell eruption.

The Upper Geyser Basin was always going to be a must-do highlight of the trip, and it delivered in every way.