Observations about the Area Above Plume Geyser March 2023

Last month I shared this photo on social media:

Social media doesn’t allow in-depth thoughts. I want to share those here. But first, I want to help you get your bearings if you still need to become familiar with the thermal features in the area.



The area above Plume Geyser and what is now “Improbable Geyser” has been full of various holes that have filled in over the years – many of which may have opened up from bison walking through the area.

Improbable Geyser

“Improbable Geyser” used to be known as “Pathetic Little Hole,” or PLH for short. It would occasionally spit up a bit of water and, in July 1988, acted more as a geyser with regular eruptions reaching up 1-2 feet. When it burst out as a major geyser in 2005, it garnered the informal name “Improbable Geyser” because it was so improbable that PLH would ever develop into anything. Eruptions from this geyser are rare; the largest eruptions happened soon after it broke out so suddenly onto the scene.

Plume Geyser

Plume Geyser was a delightful geyser that would give 4 or 5 bursts during each eruption about every hour. It broke out in the 1920s and was active for a couple of years. In the early 1940s, it began having regular eruptions in a thin jet of water that reached about 40 feet. In 1973 it expanded its crater and began having wider eruptions in bursts. Then, in January 2013, it started to have powerful eruptions captured on the streaming webcam that had up to a dozen bursts and broke itself somehow. Not much debris showed on the surface, so it likely ruptured the plumbing somewhere down below. Or at least that’s my guess. Water is now visible in the vent with constant splashing, so it may repair itself slowly.

“Tangram Geyser”

“Tangram Geyser” In 2015, to the “left” of Plume Geyser (as you look at it from the lower boardwalk), a small, steady jet of water hissed through a small hole about the size of a bottle cap. Over two years, it broke off bits and pieces of sinter with its regular eruptions. They broke off in quite geometrical shapes giving rise to a very informal name of “Tangram Geyser.” Geysers are named for their shape, location, or behavior, and this name is descriptive of their development. Was this a different expression of the energy going to Plume Geyser? Maybe. Maybe not. But it is a change to notice.

UTFs (Unnamed Thermal Features)

Next to the boardwalk, about halfway between Anemone Geyser and Plume, in 2015, it looked like someone possibly stepped off the boardwalk and created a couple of depressions in the sinter. Those and another quite open round hole both filled back in from overflow coming over the area from above. By 2019, they were well on their way to being hidden almost entirely again.


Over on the “Improbable” side of the boardwalk, there have been a couple of areas of interest. One has been informally referred to as “Nemo” – because it looks like it’s coming out of Anemone – a reference to the movie, Finding Nemo. It has changed slightly over the years, showing potential energy that’s considering coming out…when it’s safe to do so, I suppose, just like the cartoon character.


UTFs (Unnamed Thermal Features)

The second area of interest is about halfway between Anemone Geyser and Plume (almost directly across from the two depressions that filled in) is an area that, in the past, looked like there might be thermal energy trying to reach the surface there. By 2019, it also had somewhat disappeared.

Generally speaking, I see many changes in energy shifts that take two years or more in many places. Then, one day, a sudden change occurs. Tracking the small changes is challenging. This is why I started my Geyser Basin Repeat Photography Project. This visual reference and notes allow a more reliable reference than my memory.


12 March 2023 Thoughts

When I walked Geyser Hill on 12 Mar 2023, I had an hour and a half while the rest of our snowmobile tour group waited for the next eruption of Old Faithful. The weather was terrific, and my goal was to document all the thermal features you can see from the boardwalk on Geyser Hill – yet again.

When I reached the Area Above Plume, I expected to see that line of snow perpendicular to the boardwalk that I remembered so clearly from my visit in 2016. But it wasn’t there. Due to time, I couldn’t linger here and knew that photos were the best thing I could do for notes on this trip.

Looking closely at them and comparing them to other winter photos, this area might be worth a closer look whenever passing by this summer. Looking at the photo taken on 12 Mar 2023, there is a dry area – the same area above that line of snow perpendicular to the boardwalk in 2016, and that had no snow on it in 2018. It is clear of small rocks – likely from water flowing down the hill from Giantess. A small channel of water going through there doesn’t appear affected by any extra heat from below the surface, or at least not enough to dry up the stream. I would love to see what happens in this area during a light snowfall – seeing where the snow melts more quickly.

The snow had melted much more in that second area on the “Improbable” side of the boardwalk, halfway between Anemone Geyser and Plume. It even melted the snow between the boards near the boardwalk’s edge. There’s more heat from this area than in the surrounding area.



The development of new thermal features or changes in the activity of very rare geysers is sometimes a prolonged process. In my experience, shifts in many areas happen over a couple of years to decades – except in West Thumb, where changes can happen overnight without apparent warning. But even those are often a couple of years or more apart.

Looking at Plume Geyser – a geyser with enough information to give a more long-term view – can behave the same for a long time before a shift happens.

Plume Geyser:
• 1922 – First Report. A statement on Anemone Geyser is the following: “Nearby is a jagged opening in the sinter that was blown out in 1922. This is the so-called New Geyser; it was very active for two years playing every twenty minutes, but it is rarely seen of late” (Phillips, 1927, p. 144). (Marler 1973 report, p. 146)
• 1941 – Rejuvenation. Eruptions occurred every hour. (Marler 1973 Report, p. 146)
• 1959 – Response to Hebgen Lake Earthquake – Slowed down. (Marler 1973 Report, p. 146)
• 1960-1962 – Picked up its pace again (Marler 1973 Report, p. 146)
• 1972 – Expanded its crater (1986 edition of The Geysers of Yellowstone by Scott Bryan, p. 27)
• 1988 – consistency in eruptions began to change with periods of brief pauses (Landis 1987 Report, pp. 49-53)
• 2013 – Went dormant after some powerful eruptions (Personal webcam observations)
• 2015 – “Tangram Geyser” opened up near Plume (Personal observations and reports on Geyser Times)
• 2020 – roaring heard as though Plume was now a fumarole (personal observations)
• 2021 – water splashing in Plume (Video by Samsara Chapman Duffey shared to the Geyser Discussion Board on Facebook)

The bottom line is that understanding the geysers and hot springs is a long-term project. It’s wonderful that GeyserTimes is pulling together observations of eruptions, and electronic monitors on certain thermal features give us more complete data.

The more I spend time observing from the boardwalks and working on my Geyser Basin Repeat Photography Project, the more I want to gather all the bits and pieces to look for these long-term views.

Watching a small area like this and taking notes of the small changes can lead to deeper understanding once changes become more apparent.

See you on the boardwalks!

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