04 Aug 2020 Trip Report – West Thumb Geyser Basin

As life in summer gets busy, I find myself up to my eyes in projects and yet needing to get into Yellowstone to document what I see in the geyser basins. On this day, curiosity about what’s happening at West Thumb is the driving force of this “need.” Still, I also may want to spend a bit of time at Oblong Geyser that perhaps is waking from its dormancy. The webcam operators caught it in what looked like a fairly powerful eruption. Shifts in thermal energy trigger my curiosity. Here’s my field journal entry for the West Thumb portion of this trip.

This post brought to you by our sponsor, Tour Yellowstone.

Grub Steak Tours dba Tour YellowstonePrivate, custom-crafted tours.
Based out of Cody, Wyoming.
We sanitize our SUVs for your safety.
We’re ready when you are!

Route: Cody to West Thumb Geyser Basin to the Upper Geyser Basin and back to Cody.
Miles: 235
Photos taken: 945
Weather: Not a cloud in the sky to begin the day. Small, non-threatening clouds built through the day to give a welcome bit of shade.

I get a slow start to the day and am on the road at about 8 AM. There’s some traffic on the road to Yellowstone, but it’s moving nicely. In the Wapiti Valley, I look for American Kestrels on the wires. I’ve seen far fewer this year than in years past. None were seen today.

Once in the park, I pull off occasionally to list the flowers I’ve seen in bloom along the way.
• Fireweed
• Goldenrod
• Paintbrush
• Pearly Everlasting
• Lupines – looking a little ragged as they are on their way out.
• Cow Parsnip
• Pink monkeyflowers
• Monk’s hood
• Yarrow
• Sticky Geranium
• Asters
• Sulfur Buckwheat
• Harebells

1032 | As I near West Thumb, I round a corner and look over to see if any steam clouds show. None. As I reach another gap that gives a view, Lone Pine Geyser is in eruption! Grabbing my camera, I take a few “blind shots” as my eyes stay on the road. I know it will be in steam by the time I reach it.

Heavily cropped image of Lone Pine Geyser in eruption at West Thumb Geyser Basin in Yellowstone

1037 | And it is. I stop and capture it with the camera, deciding to wait until I see the last water. A family who was watching the eruption joins me, and I take the time to explain about geysers and Lone Pine. This is their first geyser ever seen.

1046 | Last splash of water from Lone Pine Geyser.

LonePine2020-08-04 10.36.25
Lone Pine Geyser in steam phase at West Thumb Geyser Basin

At West Thumb, I ran into Ranger Carley, who let me know that Waterfall Geyser is still active. Ranger Julie caught an entire eruption recently that lasted for 21 minutes (no date known).

I headed down to check on Waterfall Geyser and others in the area before meeting up with some friends. The water levels were good, and Thumb Geyser and surrounding Unnamed Thermal Features were full of muddy water indicating Waterfall is likely regularly active.

2020-08-04 11.17.23
Thumb Geyser and Waterfall Geyser area at West Thumb Geyser Basin in Yellowstone
Waterfall Geyser at West Thumb Geyser Basin in Yellowstone

1115 | Percolating Spring has a higher water level than on my last visit. But what’s more interesting to me is that it looks as though it might have been completely full recently with wet sand all the way to the rim where it reaches overflow. But perhaps it’s only damp from shifting winds and steam. A question I had when Waterfall was active before – and we knew for sure that at times Percolating Spring’s water level changed from full and overflowing to about half full. Could this be an indicator for Waterfall? Does the water rise in Percolating and lower during or after an eruption of Waterfall? Perhaps I’m just hoping for an easier way to know where Waterfall is in its cycle. We, humans, are wired to look for connections – even when there aren’t any. I don’t know if this is the case here or not. But I hope to put this theory out there for testing by myself and others who wait to catch Waterfall. 

Percolating Spring at West Thumb Geyser Basin in Yellowstone.

1118 | Perforated Pool has drops of water splashing up into view from the far back vent. The light is not on the side vent, so I’m unable to see if there’s water in there or just steam. Ephedra Spring has more water in it – enough to cover the hole on the side of the vent, but still well below overflow (at least a foot).

Ephedra Spring at West Thumb Geyser Basin

1123 | As I pause here to just watch for anything else, I notice that there’s a second small bubbler behind Thumb Geyser. The first one that has been active for a few years now lies behind Thumb Geyser and to the right. It is basically a perpetual spouter right now varying in height from six inches to one foot with a steady boil. Before, it was mostly out of sight with occasional splashes that came into view. The second small bubbler that didn’t show on my previous visit to West Thumb is located behind Thumb Geyser and to the left – and between Thumb Geyser and “Three-Lobed Spring.” The splashes from this vent are also nearly continuous, but reach only up to perhaps 6″ and is sometimes out of view.

Small geysers behind Thumb Geyser at West Thumb Geyser Basin

1147 – 1205 | I watched the mud pot in the Thumb Paint Pots area (calling it WT-MUD) erupt every 2-3 minutes for about 15 minutes. Some eruptions were more robust than others. Small ones were just a tiny lift in the level of the mud in the crater with perhaps a small splash. Others were strong enough to throw mud up a foot or two. Earlier this season, Ranger Carley said she and another ranger witnessed an eruption that tossed out mud 3-4 feet high and out nearly as far as the boardwalk. She pointed out the mud blobs that had dried at the base of one of the boardwalk supports. From the distance of the mud blobs on this visit, they seemed consistent with the one to two-foot eruptions we were seeing. After each eruption, the mud level lowered, but never drained. I witnessed a similar eruption a few years back with one of the Top Mudpots. It erupted, drained, and hissed as a fumarole and would then fill again with mud for the next cycle. This occurred every ten minutes. (See the development of this thermal feature over the years.)

2020-08-04 12.52.46
Thumb Paint Pots with WT-MUD's location shown.
WT-MUD erupting at West Thumb Geyser Basin

I then did a full photo inventory of the area. Items of note were:
Abyss Pool – I noticed it had the same amount of steam as Black Pool, and it’s leaning a bit more toward blue than green. 
Lakeshore Geyser is still underwater and full of fingerlings (fish). 
Lakeside Spring doesn’t show any sign of activity though bubbles are still rising in it. The overflow channel had good microbes in it, and the water had some color in it instead of being muddy.
Bluebell Pool is a little less green. It looks like it’s heating up again. Going through photos, it appeared blue on May 18. I didn’t visit West Thumb in June, but by July 15, Bluebell Pool was very green. I think this is the first time in 15 years of documenting West Thumb that this pool has ever been anything but blue. Water levels are still below overflow, though a wet area seems to show it may be cycling to a slightly higher water level at times. Bluebell and Seismograph are still not connected by water at the surface. 

Abyss Pool 04 Aug 2020 at West Thumb Geyser Basin in Yellowstone
Lakeshore Geyser under water in early August at West Thumb Geyser Basin.
Lakeside Spring 04 Aug 2020 at West Thumb Geyser Basin in Yellowstone
Bluebell Pool and Seismograph Pool at West Thumb Geyser Basin 04 Aug 2020
Bluebell Pool at West Thumb Geyser Basin in Yellowstone 04 Aug 2020

Stay tuned for the rest of this field journal entry that will be posted on Wednesday.

SnowMoon Photography

Be Outside • Take Notes


This site contains affiliate links. If you click on a link and make a purchase, I receive a small portion of that sale at no extra cost to you. Your purchases help to keep this site in development.




Sign up for the Yellowstone Naturalist Newsletter


Grub Steak Tours dba Tour YellowstonePrivate, custom-crafted tours.
Based out of Cody, Wyoming.
We sanitize our SUVs for your safety.
We’re ready when you are!