To see Firehole Spring, stop at the first long pullout on your left. Early explorers thought the large bubbles looked like flashes of light—hence the origin of the spring's name.

At the next parking area, view Surprise Pool. Early visitors threw sand in the pool to cause "surprise" boiling. Luckily their behavior caused no permanent damage, and you can still enjoy the deep blue color and wide intricate overhangs of sinter.

Whether Great Fountain Geyser is in eruption or not, you will see why the early explorers were so enthusiastic about this geyser's beauty. Eruptions average 100 feet (31 m) high, but some visitors are rewarded with rare "superbursts" of 200 feet (61 m) or more. Eruptions last 45-60 minutes in a series of bursts. Great Fountain takes 10-14 hours to ... Morerebuild to an eruption. The pool slowly fills, then begins to overflow 70-100 minutes before the eruption.

Like most geysers, Great Fountain experiences periods of irregularity. But, for the most part, it is dependable. While waiting for its display, watch for eruptions of White Dome Geyser to the northwest along the one-way road.
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The massive cone of White Dome Geyser indicates it has probably been erupting for hundreds of years. From such an enormous cone one might expect enormous eruptions. However, its narrow vent has been nearly sealed off with sinter deposits. Eruptions reach a height of approximately 30 feet (9 m)- the height of the entire cone. The eruption lasts abou... Moret two minutes before gradually changing into spray and steam. Intervals between eruptions are usually 30-35 minutes, but may be as long as 3 hours.Less

In the 1930s, a road was built right across the mound of Pink Cone Geyser. Fortunately this seems to have had little effect on the geyser's performance.

No record of Pink Cone erupting exists until 1887. From 1889 to 1936, it seemed to be dormant; then for the next 23 years, it erupted approximately every two days. After the Hebgen Lak... Moree Earthquake in 1959, its intervals were as short as 50 minutes with eruptions of similar duration. Through the years, the time between eruptions has increased to approximately 20 hours; the duration is about 100 minutes; and it erupts up to 30 feet (9 m).

Small amounts of manganese oxide cause Pink Cone's color. This mineral also comprises many of the brown, gray, or black deposits.
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The largest hot spring in this area, Firehole Lake, lies to your right as you enter the large parking area. Several vents supply water that averages 158°F (70°C). The water contains high levels of carbon dioxide. This allows the water to transport more calcium, which forms deposits of travertine around the lake's edge and in pearly deposits around ... Moreits geysers. The unusual black deposits are manganese oxide; dark mats of thermophiles also grow here.Less

Along the shore of this hot lake, Young Hopeful splashes almost continuously up to 2 ft (0.6 m). Other small geysers beyond this feature splash water up to 10 ft (3 m).

Artesia is a perpetual geyser that is never stops ejecting water from at least one of its two cones, usually no more than 5 ft (1.5 m). One vent is angeled toward the boardwalk that passes the geyser and the other is angled toward the Firehole River.

During a period in 1999, one of the cones jetted to a distance of 12 ft (3.7 m) while ... Morethe other emitted only steam.
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The waters across the parking lot have other surprises. Walking counterclockwise, you'll see Steady Geyser. Its mineral deposits contain calcium carbonate (appearing as travertine), silica (appearing as siliceous sinter), and manganese oxide, which causes a gray color.

A geyser within a lake: while a geyser within another body of water... More is not unique in the park, this is the largest active geyser in such a location. The extent of its activity is testified by the sinter the cone which it has built up by the deposition of sinter from its hot waters despite the hot moving water which surrounds it. This is also of interest in that water is almost constantly erupting at opposite angles from its two craters, hence the name "Steady"
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Manganese oxide also accounts for the dark color of Black Warrior Lake.

As the boardwalk reaches the end of this pool, you'll cross Hot Cascades, a steaming fall of water from Black Warrior into Hot Lake.