Field Journal Entry: West Thumb 18 May 2020

As I work through my photos and notes to add to my field journal, I’m adding in the information here as well. When the Wyoming gates opened on May 18, 2020, my first stop for documentation photos of the thermal features was at West Thumb. In this post, I share the first part of my field journal entry for that day.


With the late opening this year due to COVID-19 worries, Wyoming had the first shot at opening the summer season. The gates were scheduled to open at noon. So there wasn’t any reason to get on the road too early. So, after a leisurely morning, I found myself on the road at about 10:30 with light, high clouds in the sky.

Lilacs in town were blooming, which always makes me smile. As I went out on Canyon Avenue, I still think of Doc Howe, the Simpsons, and Grandmother who planted those lilac bushes. I rolled down my window to let the scent bring back a million memories.

In Wapiti, the elk were there in the fields. I hope this never gets so developed that we don’t see that as a typical scene. An American kestrel sat on the wires next to the road – just one seen today.

As I headed into the National Forest, spring was beginning to emerge. Bighorn Sheep hung out at the Ranger Station. Dandelions were out as high up as Blackwater. And a lone bison hung out at Eagle Creek.

Pulling up to the east entrance, I didn’t find the line of cars I expected. It turns out that they opened the gates at 10:00 to decrease congestion. 66° F at the entrance. 56° F at the top of Sylvan Pass. Talus Falls showed a thin ribbon of white water flowing down – it must have just begun. The water flows down into the snowpack from this winter.

Talus Falls 18 May 2020

Sylvan Lake’s ice is already blue as it starts to melt. And the pond below the Teton Overlook overflows in a wide swath that heads to the trees – heavier than I think I’ve ever seen. Maybe I just never noticed that before.

Ice at Sylvan Lake 18 May 2020

I start to jot down the license plates – WY (the majority), ND, IL, CO, SC, KS, NY, MT, ID, WV, NC. Traffic is light. Sedge Bay has a ribbon of open water near the shore with broken melting ice filling the rest. Ice out is still a ways off.

Sedge Bay in Yellowstone 18 May 2020

At Mary Bay, a pair of Western Grebes fed there near the shore. And I spotted the old bison that I wasn’t sure would make it through the winter. He’s distinct with the well-worn horns but quite thin this spring.

Western Grebes at Yellowstone's Mary Bay 18 May 2020

Good progress has been made on the viaduct over Pelican Creek. The large I-beams are in place, and it looks like they’re getting ready to start on the decking soon. Fishing Bridge is smoother than it’s been in years. I turn left and head to West Thumb Geyser Basin.

1234 | Lone Pine Geyser is full but barely overflowing.
1245 | On the boardwalks at West Thumb, where dandelions, yellow violas, and spring beauties dot the light green of new grass growing. I find it’s warmer than I expected. As I start around to take photos, the signs say one way around the large loop. It looks like the middle boardwalk isn’t accessible (later, I learned it was).
1249 | From a distance, I see that only one of the Mud Puffs has a cone built up, and the UTFs north of the Paint Pots Pond look nearly full. It doesn’t look like the one farthest from the boardwalk is boiling from a photo examined later.

Thumb Paint Pots 18 May 2020

1250 | Bluebell and Seismograph Pools are both hot, clear, and blue with water levels still well below overflow. There’s a wet area around Bluebell that makes me wonder if it’s cycling. There’s not much steam showing to create that, but perhaps there was earlier in the day.

Bluebell and Seismograph Pools

1251 | The “Elk Drinking Pond” (UTF Above Lakeside Spring) is unusually devoid of hoof prints in the mud along the edge. Are the elk not back in the basin yet? Or has this spring changed to where the water isn’t appealing to them? I find it interesting that they often choose to drink from here instead of the lake. I also see that the area where there used to be a small boathouse near Winter Spring (Area Above Winter Spring) has all of the small vents that surfaced here full of water again this spring with yellow monkeyflowers blooming. The rock next to Winter Spring is still above water.

An Unnamed Thermal Feature above Lakeside Spring 18 May 2020

Area Above Winter Spring 18 May 2020

1253 | UTF Near Winter Spring: A little farther along the boardwalk between Winter Spring and Lakeside Spring, I notice a round hole in the sinter that’s full of water and overflowing. I’ve never noticed this before in the 15 years of documenting this geyser basin. At Lakeside Spring, there’s light pulsing from the back vent and bubbles throughout the pool. The water appears to be reasonably clear (for Lakeside). [Video]

Unnamed Thermal Feature (UTF) near Winter Spring 18 May 2020

Unnamed Thermal Feature (UTF) Near Winter Spring 18 May 2020

Lakeside Spring 18 May 2020

1258 | The big “Lobster Pot” of “The Lobster Pots” (the line of round vents next to the boardwalk in the Venting Pools area) is full of microbes. Most of the Venting Pools are full of water. [Note: A passing visitor coined the term “Lobster Pots” one time while walking by. Ever since I’ve referred to them as such and gazers familiar with West Thumb immediately knew which thermal features these were, so I’m now using this informal name for them.]


1302 | I watch Lakeshore Geyser for a bit and notice some higher splashes from the larger vent. [Video]

Lakeshore Geyser 18 May 2020

1304 | Vandalized Spring has a larger area that’s wet around the outside of the basin as though it may have recently overflowed.

1305 | I can hear the back vent of Fishing Cone grumbling away. The side vent has microbes in the overflow, so it is active. I waited a bit before seeing any water visible – perhaps it’s cycling. Looking uphill, I can see light steam from the UTF Above Fishing Cone, but I can’t see any water.

Fishing Cone 18 May 2020

Unnamed Thermal Feature above Fishing Cone

1308 | The UTF Near Little Cone is bubbling away and overflowing. Little Cone is overflowing from the side farthest from the boardwalk and sending up bubbles that break the surface. Big Cone is lightly overflowing and sending up nice bubbles. “Tiny Cone” is overflowing with its vent full of green microbes that quickly turn to orange in the overflow channel. [Note: I use the informal name of “Tiny Cone” after hearing hundreds of visitors say, “Look at that Tiny Little Geyser!” Tiny Geyser was taken already as a name and it now has enough sinter built up to refer to it as a cone.]

Unnamed Thermal Feature Near Little Cone 18 May 2020

Little Cone 18 May 2020

Big Cone 18 May 2020

Tiny Cone 18 May 2020

1310 | Black Pool has a larger overflow area than a few years ago – the lower area has more microbes starting to grow in some of these newish channels on the lake side of the boardwalk. Microbes are growing much closer to the crater as well.

Black Pool overflow near Yellowstone Lake 18 May 2020

Overflow from Black Pool 18 May 2020

Black Pool 18 May 2020

1311 | King Geyser hardly shows any boiling, and microbes are growing in the overflow channel, so I suspect it is not erupting.

King Geyser 18 May 2020

1316 | North Star is full of orange microbes and overflowing. “Monocle Spring” has quite low water and is not overflowing as I stand here, but microbes in the overflow channel show that it does overflow. It must be cycling. I also notice the ephemeral spring up top (I strongly suspect this is the UTF Across from “Fake Fumarole) is flowing into Black Pool near the overflow from “Monacle.” [Note: The informal name of “Monacle Spring” was given to this spring by Ben Hoppe when he worked at West Thumb Geyser Basin as a Seasonal Ranger.]

1317 | The two UTFs near “Skinny Geyser” were full of water. The one closest to the boardwalk was clear of microbes and not overflowing, while the one farther had microbes growing in part of the vent and its overflow channel. “Skinny Geyser” had a bit of water showing in the vent and an area around the vent that looked recently wet.

Unnamed Thermal Features Above Black Pool and Near

1318 | Abyss Pool was NOT in overflow – something I have not seen in the 15 years of documenting West Thumb. And it was dark green with dark orange microbes showing in the “catch basin” near the main point where it overflows. On the uphill side of Abyss, a substantial area is wet from the ephemeral spring far uphill. This shows mud and debris pours into this pool. Sad to see this. In the area above Abyss with the five UTF vents, they also seem to be recipients of the flow from above. Water was seen standing in three of the five vents.

Abyss Pool 18 May 2020

Abyss Pool 18 May 2020

Abyss Pool 18 May 2020

Area Above Abyss Pool 18 May 2020

1319 | Hillside Geyser doesn’t have any microbes growing near the vent. The trees growing in this area make it difficult to view and within a few more years will obscure Hillside’s vent from view.

Hillside Geyser 18 May 2020

1322 | The Second UTF Below Twin Geyser is full of water that has an opalescent look to it. Small trees appear to be growing in the upper portion of Roadside Steamer’s crater. The UTF near Roadside Steamer is full of brown water. Another UTF above the Roadside Steamer Area has standing water in it.

Unnamed Thermal Features below Twin Geyser

Roadside Steamer Area 18 May 2020

Area Above Roadside Steamer Area 18 May 2020

1323 | The UTF Below Twin Geyser (in the photo above of the 2nd UTF Below Twin Geyser) is full of gray water and is below overflow with vegetation growing at the waterline. The right vent of Twin Geyser (only one visible from the viewing platform due to tree growth) has a wet area that looks as though it’s possibly coming from a seep on the side of the crater as there’s a carved channel in the middle of this wet area, but this also could be from precipitation.

Twin Geyser 18 May 2020

1325 | The UTF Across from “Fake Fumarole” is full of brown water but is not sending water downhill at the moment.

Unnamed Thermal Feature Across from
1327 | most of the water visible in the springs on the upper level are full of gray or brownish water. The Mimulus Pools are below full, and no boiling is seen at this time.

Unnamed Thermal Features in the Top North area of West Thumb Geyser Basin 18 May 2020

Unnamed Thermal Features in the Top North area of West Thumb Geyser Basin 18 May 2020

Mimulus Pools 18 May 2020

As I head back to the car, I again wonder if West Thumb Geyser Basin cycles basically as one unit. Many “recently wet” areas were seen. The only way I can figure to objectively learn this would be to have multiple people choose one location to watch thermal features and take observations on multiple days and then compile the observations. Without much action to watch here, though, I doubt this would be an easy thing to coordinate.


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Photo of Steamboat Geyser's eruption part way through the 33 minute water phase on 19 July 2020

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