Quick Reference Guide to Upper Geyser Basin Selected Features of Interest

Anemone Geyser

Anemone is one of the easiest geysers to see in the Upper Geyser Basin. There is usually an eruption here every 10 minutes or so. Albeit, these eruptions are small but they can teach you a lot about the workings of a geyser. Anemone is a good place to start when exploring the geyser basin.

Anemone consists of two vents that often play independently. The front, or north vent is often called Big Anemone and the back or south vent is often called Little Anemone. Big Anemone usually erupts every 7 to 10 minutes for about 45 seconds to a height of about 10 feet. Little Anemone usually erupts every 20 to 35 minutes for up to 10 minutes to a height of about 5 feet.

At Anemone, it is easy to view the normal cycle of a geyser's eruption. First, the water starts to rise in the vent. On some geysers this rise is slow on others it is fast. Next, the water begins to overflow. Some geysers do not require this step, others require a long period of overflow. Then, the geyser erupts. The eruption can end in two ways. At Anemone, the geyser runs out of steam before it runs out of water. When the energy is depleted, the steam that is driving the eruption collapses back into liquid water. This sucks the water at the surface vent back down into the plumbing system of the geyser to be reheated for the next eruption. At anemone, the suction caused by the collapsing steam is fairly strong causing a sucking sound when the water is pulled down the vent. In other geysers where the water runs out before the steam, the geyser will have a steam phase where it is mainly steam emitted from the vent with very little water. Castle is a good example of a geyser with a steam phase.

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Beauty Pool and Chromatic Pool

Beauty Pool Beauty and Chromatic are two of the prettiest pools in the Upper Geyser Basin. Beauty is especially nice.

These two pools are connected underground. Over a period of months, they alternate overflow. First one overflows while the other sits low and then they exchange and the first sits low while the other overflows. The widest range in colors is usually seen in the pool that is overflowing.

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Beehive Geyser

Beehive Geyser From a distance you notice Beehive's size and beauty, up close you are overwhelmed by its power. Either observation point is inspiring.

Beehive is one of the tallest geysers in Yellowstone. Its fine, veil-like plume has been measured to 218 feet. Because of the fine nature of the plume, the top is often knocked down by strong winds but its 5 minute eruption is always one of the highlights of the Upper Geyser Basin.

Beehive erupts from a 4 foot tall, smooth sided cone that reminded the early Washburn Expedition of 1870 of an old fashioned straw beehive. Hence, the name. Beehive erupts from a small vent at the top of the cone. This 4 inch by 10 inch hourglass shaped vent acts as a nozzle, powerfully propelling the water and steam at great velocity to its airy height. When you are standing on the boardwalk near the eruption, you feel and hear the its power. The eruption sounds like a jet engine.

For much of the past few years, Beehive has erupted at least once per day. Unfortunately, Beehive has been known to go dormant at times.

If you want to see Beehive, and I highly recommend it, there are two things you should do when you get to the Upper Geyser Basin. First, go to the Old Faithful Visitor Center and ask about Beehive. Find out how often it is playing and when it was last seen. Second, keep an eye out for Beehive's Indicator Geyser. Near Beehive's cone is a small 10 to 15 foot geyser called Beehive's Indicator. Usually, this small geyser starts 10 to 25 minutes prior to an eruption of Beehive. Rarely, Beehive starts without the indicator. On some very rare occasions during the past few years the indicator has erupted without Beehive responding but this is quite rare. While you are at the Visitor Center, also ask about Beehive's Indicator to get current information to learn how to spot it.

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Doublet Pool

Doublet Pool Doublet Pool is a pretty and sometimes fun pool. Occasionally, when there are few people on the boardwalk, it is possible to hear and feel doublet thump as steam bubbles collapse deep in Doublets plumbing system. At these periods, it is also possible to see the water over the right-hand pool pulsate.

Doublet is a good example of the one of the dangers you could encounter if you leave the boardwalk. On close examination you will notice that what initially looks like sturdy ground around Doublet Pool is actually a thin overhang of sinter over the extremely hot pool.

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Fan and Mortar Geysers

Fan and Mortar Geysers are intimately connected and usually erupt together. Fan can reach 125 feet and Mortar can reach 60 feet. The off and on eruption lasts about an hour with the most exciting part during the first 15 minutes or so. The eruption starts explosively, with both geysers quickly erupting to full height. This explosive start combined with the close proximity of the two geysers makes for one of the best geyser shows in Yellowstone, if not the world. Unfortunately, at best, Fan and Mortar only erupt every three days or so and most of the time they don't erupt even that much.

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Giant Geyser

Giant Geyser Giant Geyser lives up to its name. It is the biggest geyser in the Upper Geyser Basin and the second largest active geyser in the world. Only Steamboat Geyser at Norris Geyser Basin is larger but it hasn't erupted since 1991.

Giant Geyser's eruptions last over an hour and can exceed 250 feet. Giant is a cone-type geyser so the eruption is fairly steady. The eruption starts quickly, with the maximum height being reached in the first minute or so, then for the next hour it slowly declines. Even 45 minutes into the eruption the height has been measured to still be over 90 feet (the maximum height of a short Old Faithful eruption).

While the height of the eruption is impressive, equally impressive is the massive amount of water erupted. Giant erupts over 1,000,000 gallons of water, by comparison, Old Faithful usually erupts less than 10,000 gallons of water.

There are two basic modes of Giant eruptions. The first is Normal Function. In normal function, Giant erupts by itself. These eruptions are often shorter, only about 200 feet, but can be quite tall. The second is Mastiff Function. In Mastiff function, the closely connected Mastiff Geyser starts the eruption. First Mastiff starts, it can reach over 100 feet but recent eruptions have rarely reached more than 50 feet. Mastiff is an impressive geyser on its own right. As Mastiff erupts, Giant slowly starts filling its 10 foot tall cone. Eventually, Mastiff starts to diminish, this is when Giant takes off. It reaches its full height in one steady upward motion. Generally these are among the tallest Giant eruptions, with some reaching 250 feet or more. Catfish Geyser can also join a Mastiff Function eruption, reaching 40-50 feet. Seeing three such large geysers erupting within 75 feet of each other is an awe inspiring sight.

Between 1955 and 1996, Giant only erupted 20 times. Starting in 1996 Giant started erupting more frequently. By early 1998 the frequency of the eruptions had increased to one every 3 1/2 to 5 1/2 days. Because of this frequency, many people are willing to wait through this relatively short window with the hope that they will see this truly spectacular geyser.

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Giantess Geyser

Giantess is one of the largest and loudest geysers sometimes reaching well over 200 feet and being heard over a mile away. Unfortunately, it is relatively rare, often only erupting a handful of times per year. To complicate matters even more, it is also quite variable in the strength of its eruptions. People that have only heard about its very powerful eruptions are often disappointed if they see one of its lesser shows. They shouldn't be since even these are quite a site but when you are expecting great height and noise, a shorter quieter eruption can be a disappointment.

Giantess is a fountain-type geyser erupting from a large pool at the summit of Geyser Hill. As would be expected with its size and close proximity to the other geysers on Geyser Hill, Giantess shows a connection to many of the geysers around it.

Eruptions, which often last a day or more, fall into three types: water, steam phase and mixed. The water type consists of bursting play that lasts about 5-10 minutes and is repeated every 30-60 minutes. As the eruption progresses, the size and duration of the water bursts decreases until the eruption finally ends. The steam phase type starts as water but changes over to a loud steam phase that can easily be heard over a mile away. The steam phase slowly diminishes and ends about 6 hours after it starts. The mixed type, which seems to be the most common in recent years, starts with water, changes to steam and then changes back to water.

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Grotto Geyser

Grotto Geyser Probably the most intriguing thing about Grotto Geyser is its strange sinter formation. The large enclosing formation around the geyser was formed when dead tree stumps were coated by sinter deposited by the splashing eruptions of the geyser.

While not tall, the maximum height, usually reached at the very start of the eruption, is only 30-40 feet, Grotto's eruption can last for a long time, expelling large quantities of water. Most eruptions last 1 1/2 to 2 hours but every third or fourth eruption will last more than six hours. Some eruptions have lasted over 26 hours. Grotto is in eruption about 30% of the time.

Grotto is closely connected to the other geysers around it. Most Grotto eruptions are preceded by a very nice eruptions of Grotto Fountain Geyser and South Grotto Fountain Geyser. If the chance arises, the start of Grotto is worth watching. If it is a short duration Grotto eruption, Rocket geyser will often take over all of the activity near the end of the eruption. At these times Rocket erupts skyward to about 50 feet. If it is a long duration eruption of Grotto, Rocket usually won't erupt but eventually Spa Geyser will have bursting eruptions. All in all, the Grotto area can be a fascinating area to watch.

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Lion Geyser

Lion Geyser Lion Geyser derived its name from the roaring sound it makes before many of its eruptions. Lion is a fine example of a cyclic geyser. It erupts in a series of eruptions spaced widely apart. It is difficult to predict when the first eruption occurs but once started, it is easy to predict subsequent eruption. The first eruption is the tallest and lasts the longest. It can reach 90 feet tall and lasts about 7 minutes, ending with a short steam phase. Subsequent eruptions usually come about every 1 to 1 1/2 hours. These later eruptions are shorter and only last from 1 to 4 minutes. The first eruption is not preceded by a roar but as the series progresses, eruptions are usually preceded by louder an louder roars. While eruptions in a series are fairly predictable, there is no good way to tell when the series will end. Series can range from a rather unusual 1 eruption to over 6 eruptions.

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Morning Glory Pool

Morning Glory Pool has long been considered one of the must see attractions in the Upper Geyser Basin. While pretty, it is not the prettiest pool in the basin much less the park. Its fame came about at a time when the main road passed within a few feet of the pool. At that time it was the first attraction many visitors saw when they entered the Upper Geyser Basin. Unfortunately, this fame is also responsible for its present condition. Some visitors, unaware of how fragile the thermal features are, threw coins, rocks and garbage into Morning Glory Pool. Some of these objects found their way to Morning Glory's vent and partially clogged it. Thus, robbing the pool of a portion of its water flow. Cooling it down. As the pool cooled, algae started growing into the pool. The pool is still pretty, but you can no longer see the beautiful blues that gave the pool its name.

You can no longer drive to Morning Glory Pool. It now requires a 1.5 mile walk from the Old Faithful Visitor Center. If Morning Glory was the only thing you'd see along this walk then I question the wisdom of taking the walk, but there is much more to see along this walk than just Morning Glory. All of the geysers and pools listed on this page and many more can be seen along the trails leading to Morning Glory Pool. Take your time along these trail and watch some of the geysers. Don't just rush down the trail to get to the much publicized Morning Glory Pool. You will be disappointed if that is all that you do.

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Plume Geyser

Plume Geysers Plume is often a very regular and frequent performer. With intervals between eruptions commonly around 30 minutes, Plume provides an excellent opportunity to see a fairly large geyser at close range with very little time spent waiting.

Plume was created by a steam explosion in 1922. In 1972 there was another steam explosion that opened a new vent. This second steam explosion changed the shape of the eruption from a beautiful 40 foot plume to a still beautiful but shorter 20-25 foot burst. In 1997 almost all eruptions occurred on intervals of 23-27 minutes and consisted of 4 quick but strong bursts that each reached over 20 feet. You can check at the Old Faithful Visitor Center to get current activity information. They usually keep a close eye on Plume and should be able to give you good information.

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Sawmill Geyser

Sawmill is often the dominant geyser in the complex of geysers in the Sawmill area. At these times, when the group is in the Sawmill Mode, Sawmill Geyser is in eruption about one third of the time. Sawmill is an excellent example of a fountain type geyser, with the bursting play coming through a pool of water. Sawmill can exceed 35 feet. Eruptions commonly last 30 to 50 minutes but can last from as little as 9 minutes to over 4 hours.

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Splendid Geyser

Splendid is a major geyser. Unfortunately, most years it is very rare with only a couple eruption being seen. During an active year though, it is quite a spectacle to see. Splendid can erupt close to 200 feet for 9 minutes or more. Each eruption is different and the size and duration varies considerably. Probably the most intriguing behavior is when Splendid is active with Daisy. This most recently happened in 1997. At these times, Daisy and Splendid can erupt together. These two nearby geysers seem to try to out do each other. Each growing beyond their normal size and strength. This is one of the best shows in the Yellowstone. Unfortunately, it is rare.

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