| Note ID | Start Time (US/Mountain) | End Time (US/Mountain) | Entrant | Note |
| 41046 |
13 Aug 2025 @ 1813 |
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underarockphoto |
Mammoth Hot Springs: Minerva Terrace reactivated within the last few weeks per mhreed. Today water is emanating from a single spot partway down the terrace, flowing down for 50ft before disappearing. Fresh brilliant white calcite extends the entire length of the flow with several turquoise blue pools and some orange bacteria. Go Minerva! |
| 41035 |
12 Aug 2025 @ 1217 |
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JSJ |
Twin Butte Vista Spring (White Creek Group, Lower Geyser Basin) - visible low spouting at 1217. |
| 41006 |
11 Aug 2025 @ 1844 |
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MAB |
NGB: New Thing NNW of Black Pit- noisy more like a loud boil fry pan or even mud pot type noises - a low low popcorn growl! still splashing but not as much water flowing down the path of sands and gravels to walk as on 5th |
| 40964 |
10 Aug 2025 @ 1448 |
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Janet Jones |
Lakeside Spring is overflowing even more than two weeks ago - this is more overflow than I think I've seen in 20+ years. It is also sending up bubbles throughout the pool. Might be another one to keep an eye on since Ranger Brian did witness the water bouncing and a splash of about 2 feet a few years back. |
| 40921 |
08 Aug 2025 @ 1314 |
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JSJ |
Earthquake Geyser (Sprinkler Group, Lower Geyser Basin). Intermittent, low spouting / splashing. |
| 40899 |
07 Aug 2025 @ 1106 |
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JSJ |
UNNG-WCG-6 in the White Creek Group, Lower Geyser Basin. ~1s duration low splash at late 1106. |
| 40898 |
07 Aug 2025 @ 1025 |
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JSJ |
Twin Butte Vista Spring in the White Creek Group, Lower Geyser Basin. Low splashing / spouting visible from road. |
| 40897 |
07 Aug 2025 @ 1024 |
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JSJ |
UNNG-WCG-7 in the White Creek Group, Lower Geyser Basin. Pool's water level visible from road, but well below overflow. Two areas of bubbling / light roiling. |
| 40850 |
05 Aug 2025 @ 1855 |
--- |
MAB |
NGB: New Thing NNW of Black Pit - still splashy with waters sands and gravels flowing towards walk - trees in the vicinity showing red needles - size of the crater appears the same from the walk side to side and front to back |
| 40823 |
05 Aug 2025 @ 1643 |
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JSJ |
Active spouter in Rainbow Pool. At least 37 additional active vents between Rainbow Pool and the boardwalk (including active vents in the mouth of the runoff channel toward the boardwalk) - their activity ranged from slight bubbling to low splashing. |
| 40819 |
05 Aug 2025 @ 1006 |
05 Aug 2025 @ 1431 |
JSJ |
Silver Globe Pair Geyser (viewed from the Stock Bridge Trail, near the closed back entrance to Biscuit Basin). Active. Before the 1155 eruption & between the 1155 and 1432 eruptions, had intermittent to moderately frequent, low, brief to very brief splashing and occasional, larger bursting splashes. |
| 40851 |
05 Aug 2025 @ 0826 |
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MAB |
NGB Milky Complex - white vent downslope from brown funnel still hissing - lg feature to east still low - Glacial Melt has some cold water in it maybe rain - hole by steps boiling - Owl Eyes dry but 2023 breakout has water - Cat Eye active |
| 40791 |
04 Aug 2025 @ 0945 |
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aferrara |
Feature under Yellowstone River visible from sulphur cauldron area forcing water 2-3' up over river level. |
| 40785 |
03 Aug 2025 @ 1344 |
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JSJ |
Tonsils Spring (Tangled Geysers Group, Lower Geyser Basin) was very slowly filling and draining its basin today, repeatedly. Example: 1344 - water was out of sight. Saw this behavior last year, too. |
| 40760 |
02 Aug 2025 @ 1811 |
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JSJ |
"West Gizmo Spouter" - an otherwise unnamed perpetual spouter between Gizmo Geyser and Tortoise Shell Spring. 1811 - almost off - have never seen this before. Slightly intermittent, very small spitting only. |
| 40761 |
02 Aug 2025 @ 1726 |
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JSJ |
In the area of 3 small unnamed features ~2 to 3 meters to the right of Singlet Geyser (as seen from the Doublet bench). High-pitched, tiny spitter at 1726. Have seen / heard this feature in the past. Hisser at 1731, but no visible water from the features. Single visible bloop from the back crater (gray-colored) at 1732. |
| 40731 |
01 Aug 2025 @ 1555 |
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Geyser Guy700 |
Monument Geyser Basin- lots of loud sizzling basins across the valley floor. Monument geyser cone steaming quite loudly |
| 40702 |
30 Jul 2025 @ 1730 |
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Geyser Guy700 |
Thermopolis terraces, quietly overflowing into the river. The bath waters are nice and warm! |
| 40671 |
27 Jul 2025 @ 1842 |
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MAB |
NGB: Bubbling Bog between SB trough and Black Pit New Thing - appears dry - noises may appear if it rains but it doesn't seem to have its own water - no flow coming down that channel towards the path - nice flowers in there though this week was yarrow and some type of goldenrod |
| 40654 |
27 Jul 2025 @ 1837 |
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MAB |
NGB: New Thing NNW of Black Pit - good lighting with clouds reducing the shade - more sands at the boardwalk obstruction, crater appears bigger to the back side - crater doesn't seem wider to the south but is more visible from the Echinus steps |
| 40496 |
19 Jul 2025 @ 1849 |
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MAB |
NGB: New Thing NNW of Black Pit- more visible from Echinus junction now - view below from trail |
| 40487 |
19 Jul 2025 @ 1408 |
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MAB |
NGB: East Fork Tantalus Cr muddy at bridge with sediments. No sign of NBK10 |
| 40480 |
19 Jul 2025 @ 0813 |
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MAB |
NGB: Milky Complex- white vent still hissing - hole by steps lots of bubbling |
| 40392 |
13 Jul 2025 @ 1902 |
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MAB |
NGB: Bubbling Bog audible small boils like popping bubbles |
| 40391 |
13 Jul 2025 @ 1853 |
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MAB |
NGB: New Thing NNW of Black Pit - easily seen from Echinus stairs - crater obviously enlarged since last week with 3-4ft bursts on left side and 2ft center bursts - still cannot see if right side has enlarged - old snag suspended over the crater is not there blocking the view - examining photos I don't believe it broke and fell in, but more like rolled downhill naturally or not - more to come when I examine pics more carefully |
| 40378 |
13 Jul 2025 @ 1440 |
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MAB |
NGB: Tantalus Creek at Vixen muddy with lots of new sediments - will check on Tantalus G on my way out but could be from SB increased minors? |
| 40367 |
13 Jul 2025 @ 0808 |
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MAB |
NGB: Milky Complex white vent below the brown funnel still hissing with forced steam- steam still visible in heat of the day leaving 1417 |
| 40343 |
12 Jul 2025 @ 1348 |
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aferrara |
small muddy pools near abyss: all but two water out of site, all boiling energetically |
| 40342 |
12 Jul 2025 @ 1340 |
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aferrara |
vent on side of fishing cone bubbling a few inches over level of the lake |
| 40263 |
06 Jul 2025 @ 1926 |
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MAB |
NGB:Bubbling Bog between Black Pit and SB bridge audible and visible Bubbling but only in the far end away from bwalk |
| 40258 |
06 Jul 2025 @ 1400 |
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MAB |
NGB - all morning - Tree Island G Not IE - hereafter I will only note when it IS erupting |
| 40236 |
05 Jul 2025 @ 1713 |
05 Jul 2025 @ 1719 |
atomic7732 |
timed 10 consecutive intervals and 11 eruptions of "new imperial" geyser
average interval for this period was 35s, with median 32s, min 27s and max 57s (occurred when there was basically one bubble and then didn't erupt for 19s)
average & median duration was 13s, min 9s, max 23s |
| 40190 |
02 Jul 2025 @ 2048 |
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cb |
tree island Geyser is NOT active |
| 40134 |
28 Jun 2025 @ 1923 |
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MAB |
NGB: Tree Island G not IE |
| 40133 |
28 Jun 2025 @ 1857 |
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MAB |
NGB: New Thing NNW of Black Pit- IE on right and center areas - steady one inch ribbon of water coursing thru the sands below and reaching the boardwalk |
| 40117 |
28 Jun 2025 @ 1459 |
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MAB |
NGB: high pressure vent in Milky Complex still cooking |
| 40114 |
28 Jun 2025 @ 1220 |
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MAB |
NGB: Tree Island G not IE |
| 40097 |
28 Jun 2025 @ 0932 |
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aferrara |
Muddy spring at North West end of Mary Bay thermal features jetting narrow stream of mud about three feet high, stopped before 1015. |
| 40106 |
28 Jun 2025 @ 0832 |
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MAB |
NGB: Tantalus Creek at the bridge fairly muddy - will edit if I see something at Tantalus Geyser this afternoon |
| 40105 |
28 Jun 2025 @ 0826 |
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MAB |
NGB: New Thing NNW of Black Pit vigorous splashing center and right side- slightly cloudy water and wet sands and gravels below |
| 39987 |
21 Jun 2025 @ 1514 |
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aferrara |
are collapsing spring and pool the same thing? West Thumb collapsing blue and steadily boiling all over above vent |
| 39986 |
21 Jun 2025 @ 1511 |
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aferrara |
blue, still water |
| 40163 |
21 Jun 2025 @ 0900 |
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JarnoO |
(generic time): "On the morning of Saturday, June 21, visitors at Grand Prismatic Spring in Yellowstone National Park observed a bison slip into a shallow part of the hot spring. Clearly alarmed by the hot water—up to about 89 °C (192 °F), which is just below boiling temperature at that elevation—the animal stumbled as it tried to get out and ended up stepping into an area of deeper water and quickly perished.
Yellowstone National Park officials decided not to remove the carcass. [...]" |
| 39970 |
20 Jun 2025 @ 1813 |
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MAB |
NGB: New Thing NNW of Black Pit - more visible from steps - increased gravels pushed towards path with splashing seen on right side AND in middle of the feature |
| 39944 |
20 Jun 2025 @ 0830 |
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MAB |
NGB Tree Island G not IE |
| 39941 |
20 Jun 2025 @ 0812 |
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MAB |
NGB: don't usually make Notes for Milky Complex but sm thing by stairs bubbling - larger feature mid stairs water level lower than last week and mud pot type feature behind it a hissing high pressure steam vent |
| 39934 |
19 Jun 2025 @ 1054 |
19 Jun 2025 @ 1115 |
steve |
Iris (or what I think is Iris)is having one to three small splashes every few seconds to every one to two minutes. |
| 40028 |
19 Jun 2025 @ 0929 |
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Siegmund |
Old Bellefontaine Geyser: crater empty, gently puffing steam. |
| 39865 |
13 Jun 2025 @ 1832 |
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MAB |
NGB: New Thing NNW of Black Pit crater seems enlarged now splashing muddy water on the right side towards Black Pit |
| 39840 |
13 Jun 2025 @ 0941 |
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MAB |
NGB Tree Island G not IE although Whirligig is getting water from somewhere - seen from above w less steam @1148 wash area around it has chunks of sinter |
| 39832 |
13 Jun 2025 @ 0833 |
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MAB |
NGB: New Thing NNW of Black Pit more gravels washed on left side below crater past boardwalk- also a clear hot spot more North under some bison pies - have flir |
| 39831 |
13 Jun 2025 @ 0832 |
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MAB |
NGB: Bubbling Bog still steaming but didn't hear boils or fry pan noises - flir shows warm water not flowing thru grasses towards boardwalk |
| 39760 |
08 Jun 2025 @ 1844 |
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MAB |
NGB: Bubbling Bog NW of new thing may not be pushing warm waters thru the grasses now per FLIR- will check again on a cool morning |
| 39759 |
08 Jun 2025 @ 1840 |
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MAB |
NGB: New Thing NNW of Black Pit- thin stream of water now coursing thru the original gravels on left side below the feature with gravels reaching the path - don't know if more gravels came out or if water just pushed them farther down. |
| 39738 |
08 Jun 2025 @ 0815 |
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MAB |
NGB: Milky Complex water level down - incl dry Owl Eyes - except Cat Eye IE very vigorous though |
| 39735 |
08 Jun 2025 @ 0813 |
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MAB |
NGB: Tree Island looks full very steamy but not IE - low low Whirligig prob confirms it's been a bit |
| 39698 |
05 Jun 2025 @ 1918 |
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MAB |
NGB: Tree Island G NOT IE |
| 39697 |
05 Jun 2025 @ 1823 |
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MAB |
NGB: Bubbling Bog N of new thing and SSE of Steamboat trough still audibly bubbling with warm water coursing through the grasses towards the path - ALSO the spring slope open area just past it {towards Echinus} shows more seepage and green algaes - and mosquitoes |
| 39696 |
05 Jun 2025 @ 1817 |
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MAB |
NGB: New Thing NNW of Black Pit - more visible from steps above Black Pit - strong center splashing - waters run towards path directly below crater - some gravels have been dislodged but it hasn't broken through the gravel rim - will study pics to see if it enlarged on right side |
| 39588 |
31 May 2025 @ 1751 |
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mhreed |
Black Hermit Cauldron. Low water level, thick, muddy, and boiling. |
| 39507 |
29 May 2025 @ 1848 |
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MAB |
NGB: Tree Island G still not IE |
| 39503 |
29 May 2025 @ 1836 |
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MAB |
NGB: Bubbly Bog still making sizzle noises and pushing warm water down to and under bwalk - skeeters found me too |
| 39502 |
29 May 2025 @ 1825 |
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MAB |
NGB: New Thing 70' NNW of Black Pit- splashing now visible from steps at Black Pit - splashing more from center than left side |
| 39483 |
29 May 2025 @ 1333 |
29 May 2025 @ 1645 |
MAB |
NGB: Tree Island G not IE |
| 39472 |
29 May 2025 @ 0820 |
29 May 2025 @ 1244 |
MAB |
NGB: Tree Island G not IE |
| 39332 |
24 May 2025 @ 1853 |
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MAB |
NGB new thing NNW of Black Pit: Crater seems same size - water below bwalk definitely comes from the channel on the other side of the tree not just below the crater - still actively splashing - larger splashes on left side |
| 39331 |
24 May 2025 @ 1850 |
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MAB |
NGB: New bubbling Bog thing more like noisy bubbles and fry pan noises than this morn- could not see water going down slope as seen w steam and FLIR this morn - lg pine just behind w red needles - EDIT after examining photos - there is only one viewpoint where you can see the channel in the grass - that flow comes from the area on the right not the more open area on the left |
| 39327 |
24 May 2025 @ 1511 |
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MAB |
NGB: Tree Island G not erupting |
| 39312 |
24 May 2025 @ 1310 |
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TSBryan |
"White Sand Spring" (UNNG-BSB-8) bubbling and slightly pulsing |
| 39303 |
24 May 2025 @ 0858 |
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MAB |
NGB: Tree Island Geyser obviously IE - full steam fest |
| 39298 |
24 May 2025 @ 0821 |
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MAB |
NGB: New Boiling Bog seen by TSB yesterday north of 1969 Annex of the Annex north of 1968 Black Pit Annex north of Black Pit. Audible boils and pushing out hot water in a thin stream towards bwalk |
| 39281 |
23 May 2025 @ 0848 |
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TSBryan |
New Thing North of Black Pit vigorously splashing from 2 (3?) vents, but no runoff. |
| 39280 |
23 May 2025 @ 0845 |
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TSBryan |
Boggy area NNW of the New Thing North of Black Pit (needs a designation) steaming and, I think, faintly hissing. |
| 39275 |
23 May 2025 @ 0828 |
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TSBryan |
Tree Island not erupting; also not i.e at 1010 |
| 39245 |
21 May 2025 @ 1702 |
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MAB |
NGB: Tree Island Geyser full with steam but not erupting |
| 39225 |
21 May 2025 @ 1331 |
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MAB |
NGB: Geyser towards Tree Island NOT IE! Not drained but definitely lower water level |
| 39219 |
21 May 2025 @ 1029 |
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MAB |
NGB: Geyser by Tree Island now IE w BIG BURSTS totally flooding the Pinwheel channels all the way INTO Whirligig |
| 39212 |
21 May 2025 @ 0847 |
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MAB |
NGB: New Thing NNW of Black Pit has enlarged its crater - the poor little tree on the edge fell in! Possibly also heating up below it NW beyond the snag that collected gravels - more water flowing towards path w one wet area slightly steaming - could be from the increased splashing that direction or snow & rain could have provided the water but not the heat - will look again end of day |
| 39208 |
21 May 2025 @ 0832 |
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MAB |
NGB geyser by Tree Island NOT IE |
| 39074 |
15 May 2025 @ 1637 |
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bbev |
New breakout ~ 70' north of Black Pit erupting 12-16" from 2 separate vents. water is brown in color. Opening is about 2'x4'. |
| 39021 |
12 May 2025 @ 1850 |
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MAB |
Black Pit Annex New Thing - wetter below boardwalk - nice visible splashes in crater - sandy pools west below bw bubbling |
| 39019 |
12 May 2025 @ 0920 |
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MAB |
Possibly an incarnation of Black Pit Annex of the 60s - splashes more visible and area below crater wetter than Sat 10th - phone GPS gives distance at 82 and 83 ft NNW of the edge of Black Pit |
| 38961 |
10 May 2025 @ 1744 |
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MAB |
NEW breakout ~70ft N of Black Pit on the same elevation. Will add more later w times from photos |
| 38974 |
10 May 2025 @ 1108 |
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Janet Jones |
Percolating Spring at West Thumb was empty of water. It was full and percolating regularly last year. |
| 38975 |
10 May 2025 @ 1108 |
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Janet Jones |
"Oil Slick Pool" at West Thumb Geyser Basin was completely empty of water, though water could be hear gurgling just out of sight. |
| 38978 |
10 May 2025 @ 1100 |
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Janet Jones |
The orange pool north of Thumb Paint Pots was thumping loudly last fall with the water sounding very deep as the thumps came out of what seemed to be a cave forming. This spring it is full of water and looks sort of like a mini Dragon's Mouth Spring with water sloshing out of the overhang. Overall water levels in the Paint Pots area are very high with the "Paint Pots Pond" overflowing into the first pool to the north. Again, as with Surging Spring, the water levels are about as high as I've seen them. I would need to check photos, but I think there was only one other time they were this high and Surging was active then - maybe around 2009? |
| 38819 |
03 May 2025 @ 1040 |
03 May 2025 @ 1830 |
MAB |
NGB the "Tree Island Geyser" UNNG - I couldn't see if it was IE walking through at 0850 but on return saw it with huge bursts at 1040, continuing and photo-bombing shots of every other feature until I left for Back Basin again around 1400. Walking out it was NOT in eruption around 1830 |
| 38746 |
02 May 2025 @ 1201 |
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aferrara |
West Thumb parking lot feature - boiling violently 2-3' high |
| 38744 |
02 May 2025 @ 1135 |
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aferrara |
Blue Funnel Pool - 2-3' of crystal blue water broken by an occasional bubble |
| 38743 |
02 May 2025 @ 1134 |
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aferrara |
Thumb Geyser - opaque and greenish water |
| 38742 |
02 May 2025 @ 1132 |
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aferrara |
West Thumb - Small, muddy pool between Surging and Collapsing Springs, a few feet from edge of Surging, full of boiling turbid water. |
| 38740 |
02 May 2025 @ 1127 |
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aferrara |
Thumb Paint Pots - at edge of paint pots a feature is noisily sloshing and thumping against an overhang. |
| 38623 |
25 Apr 2025 @ 1011 |
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DanS |
Shelf Spring: visible boiling and small splashing from North side of pool. |
| 38491 |
19 Apr 2025 @ 1200 |
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Graham |
Fountain Group. The vent at the bottom of the stairs has been gurgling noisily all day. |
| 38430 |
10 Apr 2025 @ 1542 |
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SantaFe108 |
Lava Pool is full. Lava Pool Spouter erupting water with loud chugging noises. |
| 38349 |
01 Mar 2025 @ 1622 |
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K.Cooper |
Gibbon Meadows Feature not ie |
| 38337 |
28 Feb 2025 @ 1650 |
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aferrara |
small pool ~1' across between jagged and green spring boiling 6-8" |
| 38268 |
23 Feb 2025 @ 1605 |
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K.Cooper |
Gibbon Meadows Feature not ie |
| 38280 |
23 Feb 2025 @ 1456 |
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K.Cooper |
New feature behind NPR8 audibly gurgling and light thumping |
| 38256 |
18 Feb 2025 @ 1418 |
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aferrara |
crater opposite side of boardwalk from Depression (Blowout Geyser?) has standing, simmering water |